Office 2021 Quit Working on my MBP

I have a stand alone Office 2021 installation which came with a perpetual license but apparently perpetual does not mean the same to MS. I received an MS autoupdate today (like many in the past) and my apps, Word and Excel, are now unusable. I can open files but not edit or save them. I was on the phone with MS for 5 hours (not a typo) to no avail. I have removed Office and all its components from my MBP(OS 27.0.1) and used the MS license removal tool and then reinstalled Office, again to no avail. I get a message saying "Your Office 2021 license is not supported". Signing out and back in gets me the message "Couldn't refresh license, Error Code 16". MS had no idea what to do or what that error code meant. They finally told me that macOS 27 was not compatible with Office 2021 and to buy 2024 or 365.

Are others experiencing this? I could buy Office 2024 for $195 but gee, the perpetual 2021 should work.

Feedback much appreciated. Thanks...