When I tried to run Disk Utility on my 2020 Intel Air running Monterey I got:
Running First Aid on ..
Google found exactly one reference to this in a 2021 Apple Discussion post with a link to an Apple Support article that has since been removed ...
... That turned out to the known issue linked with the T2 Security chip (https://support.apple.com/en-us/HT203127). Resetting the SMC solved that problem as well as the original problem with the hard drive.
Resetting SMC (I used two methods) fixed the bug and First Aid was able to continue. (There are other problems, but at least this one was fixed.)
I don't know if this insanely rare or if Google simply isn't that useful any more (probably both). Resharing here.