When creating branches with names containing non-ascii characters, e.g. "teståäö", or when they get checked out, the indicator of the current branch disappears from the sidebar, and the current branch's name is not bold. There's no way to see which branch you're on other than using the terminal (since the status bar seems to have gone in this version of Sourcetree).

Symptom not apparent when creating/checking out branches named with only ascii characters, like "testaoeu".