+Sign Inside Circle on Edit Bar Across Top

[Steve Bolivar]

Whenever I have more than three edits open a circle with a plus sign appears over the X of the right most edit tab in place of the +tab that used to be there. The new circle+ is right over the X(close) of the edit tab that's furthest to the right and makes it impossible to close that edit. Waveform now gets confused when I switch edits. If I click on edit tabs or close edits, sometimes it doesn't update to the edit I'm working on. This started last night after I undocked an edit, but I'm not sure it's related. Closing Waveform, restarting computer didn't clear it. I looked through the manual and couldn't find anything.
Thanks for any help.
Waveform 9.3.2, Win10