InDesign Save As Issue

Having a 'Save As' issue since my last update (14.0.2).

I open an existing file to use as a template. Click 'Save As', rename the file and save onto my desktop or server. Usually the original file which I opened would now effectively close, I can continue to make changes to the file and when I hit 'Save' it will save over the new version which I have renamed.

However it is saving the new version as a copy and the old version stays open. So if I make changes and hit 'Save', it overwrites my original copy.

Everyone else in my office has tried the same thing and they're not having this issue. I've checked my preferences and I can't see anything that would help me.

Same thing happens with new documents. It'll create a file 'Untitled 1' for example. I hit 'Save As', rename the file and save to desktop. The filename at the top of my InDesign window continues to read 'Untitled 1' rather than my new filename.

Anyone got any ideas?