All sheet editing when not selected

[AZAIR]

I have recently switched over to office 365 and am now having a random issue with excel. Approximately once a week or so (I'm using excel daily) without warning or any other notification all my pages are acting like they're selected. Very frustrating because I only realize this after changing pages to find data all over. When it happens I can clearly verify that only one page is highlighted yet all pages are being changes as if I had them all selected. If I exit and reopen I have a 50/50 chance of it stopping. The only fix I have found so far is keep closing and opening until it stops. Anyone have any ideas?

[Special-K]

Are there VBA macros in the file?