[wdfifteen]

I've tried to find help on line. Microsoft seems to want to hand you off to some 3rd party help center. Web sites are so good at disguising themselves I'm not really sure I get to Microsoft at any of the URLs that look like Microsoft. I've followed the rabbit holes until I got to the (apparently) ubiquitous "We have to take control of your computer to address the problem, please allow access." No effing way am I turning my computer over to anyone.
So where does one go to get dependable, honest advice with problems with Office 365?
I keep all my files on my computers locally.
365 still works fine on all other computers in our organization, including my desktop.
On my laptop Excell, and only Excell, has lost the ability to find recent files. If I want to open something I've worked on 10 minutes ago I have to search the whole computer to find it (unless I remember where I put it in - not always the case).
My laptop is a MacBook Pro running OS 10.14.2
Desktop is a 27" iMac Retina running OS 10.12.6
Assuming the problem is some corruption of Excell, if I simply put Excell in the trash, will 365 automatically "update" (reinstall) it?
Thanks for any help you can offer.