Hi,
Kindly note that Q&A forum only support topics shared on the homepage and your problem with Excel should be assisted in following Answers forum. Kindly create a new question there is more assistance needed.
Microsoft 365 and Office
https://answers.microsoft.com/en-us/msoffice/forum?sort=LastReplyDate&dir=Desc&tab=All&status=all&mod=&modAge=&advFil=&postedAfter=&postedBefore=&threadType=All&isFilterExpanded=false&page=1
Per searching, it is instructed that following type of files will be open in Protected View by default.
- originate from the Internet
- are located in potentially unsafe locations
- are received as attachments to an e-mail message
However, by going to File>Options>Trust Center>Trust Center Settings>Protected View, you can change that behaviour for each of the above individual cases.
If the documents have the Read-only attribute set, you can go to File>Options>General and uncheck the box for "Open e-mail attachments and other uneditable files in reading view".
Hope this helps and please help to accept as Answer if the response is useful.
Thanks,
Jenny