In my case there was a weird authentication issue. I am not sure what EXACTLY happened but…
I had to do an ad-hoc demo on another person’s laptop so I signed into my Glide account on their laptop using google which authenticate to my phone. Being paranoid I logged out of all devices for google (logging out ALL google apps including drive) and then reset my google password. At this point I believe I disconnect the authentication between google and Glide. Everything had access - but could not authenticate. So google tables failed and Glide tables worked.
After a panic of a day (clearing caches and all the other activities) I signed into Glide using my google account (not email which I normally do) and access to drive/sheets worked. I had somehow disconnected authentication between Google and Glide and thankfully got reconnected when I used Google authentication to sign into Glide.
BTW - this is the thread where I described the process that I used to clear google off all devices/services (and which caused all my problems) if that helps. Log out all developers - #6 by MattLB
Good luck!