Hi @groucho777
Does this issue occur with specific templates or all presentations?
Please go to SlideMaster View, choose one Placeholder, right click it, in Text Options, make sure "Do not Autofit" is not ticked.
Then I suggest you check this issue in Safe Mode of PowerPoint:
- You can press and hold on Ctrl key, click or double-click PowerPoint icon, until it asks if you want to start it in safe mode, then please release Ctrl key and click "Yes".
Safe mode can eliminate the impact of third-party add-ons.
- If this issue does not persist in Safe Mode, please click: File > Options > Add-ins > Manage COM Add-ins, click Go, clear the check boxes for any enabled COM add-ins, select OK.
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