"Cmd+Enter" when leaving a comment fails to clear the locally-saved comment text

Summary

When I press cmd+enter to submit a comment in an issue/MR discussion, the text of that comment reappears the next time I go to leave a comment.

Steps to reproduce

1. Start a new discussion thread
2. In the discussion thread, compose a comment, then click "Comment".
3. Click in the text box to start composing another comment. Notice that it is empty.
4. Compose a second comment, then type cmd+enter.
5. Click in the text box to start composing another comment. Notice that your previous comment is still in the text entry box.

Note that this only seems to happen in threads, and only within a single thread.

Example Project

This occurs on any project (see screen recording below for an example). An example project link isn't too helpful here, since the bug depends on the user's browser state, not just the server-side project state.

What is the current bug behavior?

The previously-entered comment in a thread still appears.

What is the expected correct behavior?

The text entry box should be empty.

Relevant logs and/or screenshots

Screen_Recording_2020-05-05_at_3.21.42_PM

Output of checks

This bug happens on GitLab.com