User losing check-out ownership; can't check-in...

Occasional Contributor

We have a user who checks-out Excel spreadsheets from a SharePoint 2016 document library, but when she checks them back in, SharePoint thinks somebody else has it checked out and won't let her check it in.   Why might this be happening over and over?  how can we troubleshoot?  what logs can we look at? or have generated (or enabled if need be)?  

2 Replies
I guess the first question is , why is the user checking out the file? I would say 99% of the time, it’s not needed

But if your an admin….
Disregard my question as it seems your on onPrem.

It’s still not needed