[BUG REPORT] Cannot switch tabs in PowerPoint 2016

Question

Hi,
Recently I met a bug in tabs for PowerPoint 2016.

When opening 2 or more powerpoint files and focus on any textbox in one slide, I cannot switch to other tabs, no matter using mouse clicks or Ctrl-Tab keybindings

Once the focus is moved, e.g. click on blank space outside a slide, the tabs can be switched without problems.

I tried to change other options in OfficeTab settings but it seemed no effects.

I am running window 10 pro x64 with creators update (build 15063) and office 2016 professional plus x64 edition

There are no similar problems when using OfficeTab with word or excel.

-Yidong