"Diff with previous version" dialog does not clear files list during validation / for invalid version

What steps will reproduce the problem?

1. From the context menu select "Diff with previous version"
2. Make sure the files list shown is not empty
3. Leave the "Version 2" field empty or enter something invalid, such as \
4. Hover over the "Wait For input validate version", respectively "... is invalid" message shown in the files list
   ❌ It still shows the hover text for the previously shown files
   ❌ Occasionally the previous file entries "flash through" (can be seen when quickly moving the mouse)
   ❌ Double clicking the space where previously a file entry was shown still opens that file

What is the expected output? What do you see instead?

Expected: During "Wait For input validate version" and when "... is invalid" is shown the previously files list should be cleared.

Actual: The files list is somehow still shown in the background causing graphical bugs and irritating behavior. See attached video TortoiseGit_Diff_with_previous_version.

What version of TortoiseGit and Git are you using? On what operating system?

TortoiseGit 2.12.0.0
git version 2.33.0.windows.2

Windows 10