Hi, I have this ongoing issue with one of our users. It just occurred one day wherein the preview of attachment stops working for a few minutes using web based Outlook O365. When he close and re-open the browser, it will work for a few minutes again (within 30 minutes of usage). User both tried it on Chromium and Chrome same issue.
Steps we tried:
Reset both browsers
Downloaded Office 365 updates
Made sure Attachment preview not disabled under Outlook Client
Did download Win 10 updates as well
Check Win defender settings
All of these steps didn't help. User prefers to use webmail instead of the client thus I want to check if anyone had encountered the same issue and what helped to resolve the problem.