Source list content width always starts very narrow, needlessly truncates text

With the 2.2. update, branch names get needlessly truncated when the source list has more than enough space to display names. I have my source list set wider than default, since my project has deeply-nested branch hierarchies (see attached screenshot).

I can work around this by dragging the source list divider to be narrow and then wide again. However, this problem recurs anytime a window is reopened or the app is relaunched.