React Native Android layout glitches with session recording #3140

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1. Nezz

   added

   bugSomething isn't workingSomething isn't working

   on Feb 24, 2026
2. ablaszkiewicz commented on Feb 24, 2026

   

   ablaszkiewicz

   on Feb 24, 2026

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   @marandaneto, @ioannisj
3. marandaneto

   added

   feature/replay

   react-native

   on Feb 24, 2026
4. marandaneto commented on Feb 24, 2026

   

   marandaneto

   on Feb 24, 2026

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   thanks @Nezz will try to reproduce it

   🚀React with 🚀1Reacted by Adam Kapos
5. marandaneto commented on Feb 26, 2026

   

   marandaneto

   on Feb 26, 2026

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   The PostHog Android SDK's session replay takes screenshots via PixelCopy on every throttled draw. The old code created and destroyed a new HandlerThread for every single screenshot (~1/sec). The PixelCopy callback then
   traverses the entire view tree from that background thread to find maskable widgets.

   On Android 15+, which enforces edge-to-edge, this thread churn combined with background view-tree access creates a race condition where rootWindowInsets briefly returns zero values. Since react-native-safe-area-context
   reads these insets via OnPreDrawListener, the safe area periodically flashes to zero, causing the UI to jump.

   This explains why:

   • Increasing androidDebouncerDelayMs helps (fewer screenshots = less thread churn)
   • Debouncing useSafeAreaInsets() helps (masks the transient zeros)
   • Disabling session replay fixes it entirely
   • It only happens on Android 15+ (edge-to-edge enforcement changed insets dispatch)

   The fix (in posthog-android):

   1. Reuse a single HandlerThread for PixelCopy callbacks instead of creating/destroying one per screenshot
   2. Early bail-out checks (isOnDrawnCalled) at the top of generateSnapshot() and findMaskableWidgets() to minimize time spent reading stale view state off the main thread
   3. Reduce allocations during the view tree walk (reusable Rect/Point, Set instead of List for password types, contains(ignoreCase=true) instead of lowercase())

   Im not sure if this alone is enough, but might improve things
6. Nezz commented on Mar 10, 2026

   

   Nezz

   on Mar 10, 2026

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   I tried "posthog-react-native-session-replay": "1.5.1" but sadly I don't see a noticeable improvement so for now we can't enable it on Android.
7. joaqo commented on Mar 27, 2026

   

   joaqo

   on Mar 27, 2026

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   Given that the issue seems to be diagnosed, should we be expecting a fix? I'm the creator of the original issue reporting this, so I've been more than a year with no Android session replays.
8. marandaneto commented on Apr 29, 2026

   

   marandaneto

   on Apr 29, 2026

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   there were some improvements on android and ios, please try the latest version and report back if there is still an issue
9. marandaneto

   closed this as completedon Apr 29, 2026