I saw this problem a few day before and this is something that need to pay attention, the problem started when I had a multiple tab to do
a work, then I put some tabs windows and drag to the left to make my drawing more easier base on the reference on the left
and suddenly the tabs goes crazy and always started to move up
I've found the solution by autohide the taskbar, but it really not confortable because taskbar are usefull at the sametime
Known bug. Adobe working on it.