Open in Desktop App

Hi. I have an unusual problem that I can't figure out, and nor can the 4 people I was transferred between at Microsoft Support. Hoping this forum can help!

I recently bought a new Mac Mini. I also have my older MacBook Pro laptop and I cloned this to the new mac. The machines are effectively identical in as much as they are both running the same versions of Office / Teams / Sharepoint, and are logged in to the same Office365 accounts. 

On my new Mac, many of the files stored in my sharepoint account do not open in the desktop apps. They open fine within MSTeams and on Sharepoint, but when I try to open them in the desktop app, I get the non-specific error "Could not open file". This is very frustrating and although others seems to have the problem, I can't find anyone who has managed to solve this.