Changing conversion length affects preceding phrase conversion in some cases #707

Description
When I change the conversion length, it sometimes affects the conversion of the preceding phrase.

Steps to reproduce
Steps to reproduce the behavior:

1. かしごじゅうどだいなかば
2. 歌詞五重土台半ば
3. 華氏50土台半ば
4. Change the conversion length of "土台半ば"

Expected behavior
華氏50℃台半ば

Actual behavior
華氏五十℃台半ば

Version or commit-id
Mozc-2.28.5050.100+24.11.oss

Environment

• OS: Windows11

Investigations

• Whether this issue happens on other IMEs (e.g. Anthy, SKK).
  • no