Suspect PM Leaving: Career Advice?

My PM has been on a ridiculous number of personal calls and taking time off on short notice over the past few weeks. Pretty sure no personal or family issues, so naturally I’m suspecting he is leaving.

Any tips or advice for navigating something like this? We have a good working relationship so I’m almost tempted to just ask him during a catch-up as it’s causing too much anxiety and stress, but would like to hear from others.