EXCEL - Active Workbook Goes Uneditable - Hit Enter / Jumps to another workbook - Have to click back

Glad to know I'm not the only one having this problem.  I am a power user.  I'll have multiple large files open in Excel along with files in Word, Adobe and Teams.  I've learned that if Excel "stops responding" to make note of what I was editing and hit the Enter key.  Excel changes focus to another file.  I haven't noted that whether it is in edit mode for the focus cell or not.  I'll hit Escape and then return to the file I was working on.  I have not seen a cumulative effect causing any of the open file to become corrupt... crossing my fingers on that one.  So it is "just" an annoyance that needs an explanation.  It is also a recent change in the behavior of Excel, so I'm guessing an update happened that isn't quite stable.  That doesn't bode well for the future.  Hopefully Microsoft development is paying attention.  However, it is interesting to note the original post was from 2018.  So maybe not new... just new to me.  robbimj