MS word opens regular documents as templates--make it stop

I’ve been having trouble with some but not all MS Word documents recently–they have the extension .docx, but open as templates. Sometimes doing a save and replace with the same filename clears up the problem, but not every time. What’s going on and how do I make it stop?

I don’t know if this is the same issue, but a problem discussed here:

said

Is that what’s happening? If so, the suggested workaround was:

Sounds like not quite the same problem, but I will give this a try. Thank you.