Immediately after updating to macOS Monterey the issue started.

SourceTree is updated to the latest available version 4.1.9.

In the Tasks Monitor (Debug -> Show Tasks Monitor) I can see that it's exactly the diff action that freezes the whole app.

RangeRevFileDiff - duration ~40 seconds

or

RevisionFileDiff - duration ~40 seconds

Please fix it as soon as possible. SourceTree is unusable with these freezes.

Steps to reproduce:

1. Clone a public GitHub repo, for example: https://github.com/forcedotcom/salesforcedx-vscode
2. Browse the History tab in SourceTree
3. Click on different files in the commit details until the issue appears (should appear on 1-3 click)

See the video - https://drive.google.com/file/d/1ZfXRfqreteL0Apaf0ls95PdNoyYpiJQy/view