After updated to 1.8.1, the cursor sometimes misaligned with notes.

[louislam]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Sometimes the cursor misaligned with notes.

PS: GitHub muted video by default, unmuting may be able to sense the issue easier.

1.8.1miss-align.mp4

Expected Behavior

It was fine in 1.6.X, 1.7.X, 1.8.0. The cursor should always aligned to notes.

1.8.0.mp4

Steps To Reproduce

Update: I have setup an instance, in case you don't want to install deno, see #2546 (comment)

I think my AlphaTab is heavily modified, so I think the best way to reproduce is directly using my project.

git clone https://github.com/louislam/its-mytabs
cd its-mytabs
git checkout dev-alphatab181
deno task setup
deno task start

• Go to http://localhost:47777
• Play the demo tab
• You should see the issue

For reference, you can switch back to AlphaTab 1.8.0 (master branch) for comparison:

git checkout master
deno task setup
deno task start

Also here is the bass tab Guitar Pro file:
https://github.com/louislam/its-mytabs/blob/master/extra/demo-tab.gp

Link to jsFiddle, CodePen, Project

https://github.com/louislam/its-mytabs

Version and Environment

OS: Windows 11
Tested on Chrome and Firefox

[AlphaTab][VersionInfo] alphaTab 1.8.1 alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] commit: 8a2102fe7ee7dcf4b50c3a4198fbb8c0d5c0fda3 alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] build date: 2026-02-01T19:53:46.853Z alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] High DPI: 1.25 alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] Platform: BrowserModule alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] WebPack: false alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] Vite: false alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] Browser: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0 alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] Window Size: 2062x1118 alphaTab-4zmP5fZN.js:1:11392
[AlphaTab][VersionInfo] Screen Size: 2048x1152

Platform

Web

Anything else?

I suspected it is related to this #2536

[AvaTheArchitect]

Is the Public version of the 1.8.1 released yet? I think you could be on an unstable version of it at the moment? Ah, that clears it up—you're looking at the "bleeding edge." Based on the *AlphaTab GitHub PR #2536*, what you are seeing labeled as "1.8.1" in that user's ticket is an *unreleased development build* compiled directly from the develop branch. The version number was likely bumped in the source code following the 1.8.0 release to prepare for the next iteration, but it hasn't hit *npm* or *NuGet* as a stable tag yet. I could be wrong though? I am curious as well since this would impact me at the same time.

…

On Tue, Feb 3, 2026 at 9:31 AM Louis Lam ***@***.***> wrote: *louislam* created an issue (CoderLine/alphaTab#2546) <#2546> Is there an existing issue for this? - I have searched the existing issues Current Behavior Sometimes the cursor miss aligned with notes. https://github.com/user-attachments/assets/2b3ec5b5-e2d5-4249-8d65-cc52d9bea57f Expected Behavior It was fine in 1.6.X, 1.7.X, 1.8.0. The cursor should always aligned to notes. https://github.com/user-attachments/assets/dcc98fd5-7d62-4878-a43b-3f63959c05e6 Steps To Reproduce I think my AlphaTab is heavily modified, so I think the best way to reproduce is directly using my project. git clone https://github.com/louislam/its-mytabscd its-mytabs git checkout dev-alphatab181 deno task setup deno task start - Go to http://localhost:47777 - Play the demo tab - You should see the issue For reference, you can switch back to AlphaTab 1.8.0 (master branch) for comparison: git checkout master deno task setup deno task start Link to jsFiddle, CodePen, Project *No response* Version and Environment [AlphaTab][VersionInfo] alphaTab 1.8.1 alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] commit: 8a2102f alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] build date: 2026-02-01T19:53:46.853Z alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] High DPI: 1.25 alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] Platform: BrowserModule alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] WebPack: false alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] Vite: false alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] Browser: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0 alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] Window Size: 2062x1118 alphaTab-4zmP5fZN.js:1:11392 [AlphaTab][VersionInfo] Screen Size: 2048x1152 Platform Web Anything else? I suspected it is related to this #2536 <#2536> — Reply to this email directly, view it on GitHub <#2546>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BNLESQA3ETQE3WI4DPSRQYT4KDLOZAVCNFSM6AAAAACT3CQ6YCVHI2DSMVQWIX3LMV43ASLTON2WKOZTHA4TEMRYGU4TAMY> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[louislam]

I have never used an unstable version. It is literally 1.8.1 on npm.

1.8.1 had been released 2 day ago.
https://www.npmjs.com/package/@coderline/alphatab/v/1.8.1
https://github.com/CoderLine/alphaTab/releases/tag/v1.8.1

The reason why I suspected this PR, because it mentioned "cursor" in the changelog in #2515, and then it was closed by #2536.

Of course, I didn't look into it deeply, I could be wrong too.

[AvaTheArchitect]

Thanks for confirming! I was looking for that but didn’t get the usual updates when it pushed out. I have a different issue currently in which my cursor is getting stuck on the last measure of a row, such as a half rest or whole rest or even partially stuck on an 8th note in the last measure but never saw that before.

…

On Tue, Feb 3, 2026 at 7:10 PM Louis Lam ***@***.***> wrote: *louislam* left a comment (CoderLine/alphaTab#2546) <#2546 (comment)> I have never used unstable version. 1.8.1 had been released 2 day ago. ***@***.***/alphatab-monaco/v/1.8.1 https://github.com/CoderLine/alphaTab/releases/tag/v1.8.1 The reason why I suspected this PR, because it mentioned "cursor" in the changelog in #2515 <#2515>, and then it was closed by #2536 <#2536>. Of course, I didn't look into it, I could be wrong too. — Reply to this email directly, view it on GitHub <#2546 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BNLESQGPLPGP7OHHZYGKRET4KFPL3AVCNFSM6AAAAACT3CQ6YCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTQNBUHE4TCNRYGA> . You are receiving this because you commented.Message ID: ***@***.***>

[AvaTheArchitect]

Yep sure enough when I updated two days ago it must have slipped through to public right after so I was testing on beta which I normally never do.

…

On Tue, Feb 3, 2026 at 7:10 PM Louis Lam ***@***.***> wrote: *louislam* left a comment (CoderLine/alphaTab#2546) <#2546 (comment)> I have never used unstable version. 1.8.1 had been released 2 day ago. ***@***.***/alphatab-monaco/v/1.8.1 https://github.com/CoderLine/alphaTab/releases/tag/v1.8.1 The reason why I suspected this PR, because it mentioned "cursor" in the changelog in #2515 <#2515>, and then it was closed by #2536 <#2536>. Of course, I didn't look into it, I could be wrong too. — Reply to this email directly, view it on GitHub <#2546 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BNLESQGPLPGP7OHHZYGKRET4KFPL3AVCNFSM6AAAAACT3CQ6YCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTQNBUHE4TCNRYGA> . You are receiving this because you commented.Message ID: ***@***.***>

[AvaTheArchitect]

Now it’s interesting as I am testing both my custom cursor and the default cursor running on the 1.8.1 version. But both the cursors are aligned perfectly over every note on the different gp song files I tested.

…

On Tue, Feb 3, 2026 at 7:10 PM Louis Lam ***@***.***> wrote: *louislam* left a comment (CoderLine/alphaTab#2546) <#2546 (comment)> I have never used unstable version. 1.8.1 had been released 2 day ago. ***@***.***/alphatab-monaco/v/1.8.1 https://github.com/CoderLine/alphaTab/releases/tag/v1.8.1 The reason why I suspected this PR, because it mentioned "cursor" in the changelog in #2515 <#2515>, and then it was closed by #2536 <#2536>. Of course, I didn't look into it, I could be wrong too. — Reply to this email directly, view it on GitHub <#2546 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BNLESQGPLPGP7OHHZYGKRET4KFPL3AVCNFSM6AAAAACT3CQ6YCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTQNBUHE4TCNRYGA> . You are receiving this because you commented.Message ID: ***@***.***>

[louislam]

I have a different issue currently in which my cursor is getting stuck on the last measure of a row

I think I just saw a similar issue too, but let's focus on the alignment issue here first.

I just deploy it on my server and share here, I hope it helps you guys to reproduce the issue.

AlphaTab 1.8.1

1. Go to https://its-mytabs-dev-alphatab181.kuma.pet/settings
2. Set Cursor to "Cursor (Instant)"
3. Go to https://its-mytabs-dev-alphatab181.kuma.pet/tab/1?audio=youtube-VuKSlOT__9s&track=2
4. Play the song
5. You should be able to see the issue in first two bars (bass tab)

Also I realized that this issue always happens on Youtube/Audio file source, if I change to Synth, it rarely miss aligned (but still happen).

For comparison, here is AlphaTab 1.8.0

1. Go to https://its-mytabs.kuma.pet/settings
2. Set Cursor to "Cursor (Instant)"
3. Go to https://its-mytabs.kuma.pet/tab/1?audio=youtube-VuKSlOT__9s&track=2
4. Play the song

[AvaTheArchitect]

Hi Louis, Have you heard anything back regarding the cursor alignment issue? In my testing on version 1.8.1, both the default and custom cursors are aligning perfectly with the notes. While my previous issue was specific to a custom cursor, the default one has been working correctly for me across vocal and guitar tabs. I've recorded a video showing the correct alignment here: https://youtu.be/wyfC6bKf-hM (https://youtu.be/wyfC6bKf-hM) Best regards

…

On Wed, Feb 4, 2026 at 2:45 AM Louis Lam ***@***.***> wrote: *louislam* left a comment (CoderLine/alphaTab#2546) <#2546 (comment)> I have a different issue currently in which my cursor is getting stuck on the last measure of a row I think I just saw a similar issue too, but let's focus on the alignment issue here first. I just deploy it on my server, I hope it helps you guys to debug AlphaTab 1.8.1 1. Go to https://its-mytabs-dev-alphatab181.kuma.pet/settings 2. Set Cursor to "Cursor (Instant)" 3. Go to https://its-mytabs-dev-alphatab181.kuma.pet/tab/1?audio=youtube-VuKSlOT__9s&track=2 4. Play the song 5. You should be able to see the issue in first two bars image.png (view on web) <https://github.com/user-attachments/assets/9fd9af13-9684-4213-a1ad-f388cdb675a7> Also I realized that this issue always happens on Youtube/Audio file source, if I change to Synth, it rarely miss aligned (but still happen). For comparison, here is AlphaTab 1.8.0 1. Go to https://its-mytabs.kuma.pet/settings 2. Set Cursor to "Cursor (Instant)" 3. Go to https://its-mytabs.kuma.pet/tab/1?audio=youtube-VuKSlOT__9s&track=2 4. Play the song — Reply to this email directly, view it on GitHub <#2546 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BNLESQFMXSNRPBC4JDQTRW34KHETDAVCNFSM6AAAAACT3CQ6YCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTQNBWGY4DGMJZGE> . You are receiving this because you commented.Message ID: ***@***.***>

[AvaTheArchitect]

Update! I can now confirm the same issue, but the cursor off center issue for me is not present on all my GP files that I am using. However, for a gp3 file it is present just as @louislam has shown:
sample-songs/real-songs/ozzy-no-more-tears/ozzy-no-more-tears.gp3
Mostly some but not all double digit numbers like 12,13, but not all 12 and 13 numbers throughout are off-center it's sort of 50/50 - I could not duplicate this at all on single digit numbers 0-9 Note: And not duplicate this on guitar tab on gp5 files that I tested.

🔄 V98.32: Playback range changed, updating overlay
MaestroCursor.tsx:192 ❌ RANGE NULL at tick 88801
MaestroCursor.tsx:192 ❌ RANGE NULL at tick 89281

[Danielku15]

@louislam Just to confirm I understand the problem correctly:

1. It is a pure problem of misalignment and not a time-synchronization issue (e.g. the cursor being at the wrong note at the wrong time)
2. It only happens for the "Cursor (instant)" (non-animated beat cursor)

I have an idea how this bug could have slipped in but want to confirm things first.