Documents (Especially Word and Powerpoint) are taking a long time to open or save using Office Mac (O365 Vsn 16.80)

for the last few months it has taken a long time for documents to open from Teams using office Mac. I have a Parallels partition on my machine and the same documents open in seconds using Office Windows. Casing point I have a Powerpoint presentation with about 100 slides in it (yes larger file size - 56MB but nothing that used to be a major issue). This document opening from Teams using Office Mac took over 5 minutes to open. The same file from the same location took 26 seconds (in its entirety) using Windows. The same thing occurs when saving

Any ideas? I have looked at the forums and tried a couple of things suggested but nothing seems to have worked as yet