When committing files, there’s a list of files with an “…” (ellipsis) button next to them.

The click target (hit area) of the button is only 4 points high and can be barely clicked. See the screenshot “3.1.1” - you can only click what’s inside the grey rounded border drawn around ellipsis.

I went through SourceTree archives and pinpointed the regression to be in between version 2.5.3 and 2.6.3. See screenshots “2.5.3” where the button is drawn differently and has an adequate hit area.