Adding lots of line breaks to text area

[burakkurkcu]

Describe the bug
https://www.linkedin.com/posts/-garypalmer_another-day-another-stepwise-change-more-ugcPost-7381969261562478592-_AAc go to this post in Firefox 143.0.4 (aarch64) and try to comment "ga", as two letters doesn't mean anything I think Harper tries to underline it as error but instead adds lots of empty line breaks at the end, like almost infinite amount.

To Reproduce
Steps to reproduce the behavior:

1. In Firefox 143.0.4 (aarch64) go to https://www.linkedin.com/posts/-garypalmer_another-day-another-stepwise-change-more-ugcPost-7381969261562478592-_AAc
2. Click on comment box
3. Type "ga" (2 letters, I think anything will work that is grammatically not meaningful)
4. See error

Expected behavior
Drawing underline as error

Screenshots

Platform
MacBook M1 Pro - macOS 15.7.1 (24G231) - Firefox 143.0.4 (aarch64)

[ThexXTURBOXx]

This issue seems to be related to #1395 - however, here it seems to be even more extreme