
Hello
Thank you for addressing the issue, I understand your concern, let me help you.
To resolve this, here are few steps to follow:
- Change the Thumbnail Twice.
Edit the page → Click Page Details → Select a new thumbnail → Save. Repeat the process to ensure it updates.
- Check for Microsoft Issues.
Visit Microsoft 365 Service Health to see if there's a known problem.
- Try a JPG Image
Use JPG instead of PNG
I hope this helps, have a great day ahead of you!
Best Regards,
Tani | Microsoft Community Moderator.