Hi Frank,
As per your description, I have tested from my side I open three different PowerPoint presentation slide on mac OS and when I click one of them in presentation mode after that when I exit presentation mode and other two PowerPoint cannot pull up in my side.
Please try to opening PowerPoint for Mac in Safe Mode to determine whether background programs are interfering with any 3^rd^ partiesfor Mac.
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In order to help you further and make the issue symptom clearer, we would like to know the following:
1.Does this issue happen to all PowerPoint even newly created ones or only specific ones?
2.Could you please share with us steps how did you closing the presentation mode.
- PowerPoint application version with detail build number. (Open PowerPoint application> Click on PowerPoint in Menu bar> About PowerPoint)
- MacOS version. (Click on Apple icon> About Mac)
I appreciate your time and understanding.
Best Regards
Waqas Muhammad