IssueTracker

First of all thanks for this detailed issue.

This issue had been investigated thoroughly when it was first reported internally. The surprising detail in this report is that the issue is not reproducible before 1.7. I will look into this.

The main problem with POBox is the fact that it is deprecated. Since 2021 Sony has been shipping new Xperia devices with Gboard pre-installed. Although we are aware that there is still a considerable amount of users still using POBox, the described behavior is caused by POBox's noncompliant behavior with InputConnection and InputMethodManager documentation. However, this is understandable since TextView implementation was also not respecting the behavior that is expected from Editors.

Ultimately we have decided to enforce the documented behavior with specifically regards to when editors should call InputMethodManager.updateSelection. Also, although unconfirmed, there were traces of possible custom code being included in Sony OEM images that changed how InputMethodManager was notified from TextView. If POBox also depended on something like this, it would be impossible for Compose code to replicate the same unknown behavior.