Computer Help and Support

There was some weirdness today, spam attacks, search engines going down temporarily. My "From:" address on the mac disappeared and I had to restore it. There are days (and weeks) like this.

Oh, apparently, there's a full moon!!! 🌕

One of the web search hits should give you ideas on what might have caused it and where to start fixing.

This one mentions a "reset view" menu option (It's pretty damn detailed)
https://helpdeskgeek.com/office-tips/why-your-outlook-inbox-view-changed-and-how-to-change-it-back/

Another looks promising.
https://www.technipages.com/outlook-email-view-changed/

There are others. I have no idea where preferences are saved: on the computer, at Microsoft (outlook.com) or both.

Good luck.