I did, same. Restarted bowser, same. I restarted machine, same.
When I turned on this:
"Additional information at Scheduling page" in settings, it stopped. Now even if I turn that off, it still works - strange. But I'm not experiencing the issue any more so all good.
Might be helpful if someone else has the same issue. I'm gonna keep the additional info on BTW, that's handy.
Thanks for the reply anyway Sami.
I should add, that I had tried this "Additional information at Scheduling page" feature earlier and turned it off, as it was interrupting the mouse over window, making it disappear, this isn't happening any more. Because this is turned on by default, shouldn't affect many people.