Can only access shared files in my OneDrive

I have several Microsoft 365 accounts -- at least 2 each personal, business, and church. I'm trying to access files in my main church account in my main browser (Chrome; Windows 10). I've done this many times before, know how to do it, and have always been successful doing so -- until now.

Now when I log in at onedrive.live.com, I can log in successfully, but I don't see folders nor do I see the navigation pane on the left or "+New", Upload, Sync, nor Automate in the menu bar at the top. The only thing I see is a single shared file -- and it's not even the only shared file in the root OneDrive folder!

I figure this is due to being logged in to more than one account, but I don't know how to verify what other accounts I may be logged in to at the moment. How can I regain access to all my files?