iMac 27" keeps dropping Wi-Fi

About six months back I first started having an issue whereby my iMac 27 5K will periodically lose its Wi-Fi connection and get stuck in an endless loop trying to connect. When this happens the network services process uses up nearly all of my CPU and my system is unresponsive while the bars "search." Restarting has no effect - the Wi-Fi symbol in the menu bar continues to "search." Restarting the Mac, the access point and the router all have no effect.

Opening the network control panel takes FOREVER to open or respond and only rarely allows me to actually turn off Wi-Fi so that I can remove it and re-add (toggling off from the wi-fi symbol in the menu bar has no effect). IF I can complete this process it sometimes works for a few hours before the problem resurfaces (invariably in the middle of a Zoom call or some other critical setting).

The iMac has no connectivity issues when plugged into to an ethernet adapter. Unfortunately that is not a permanent solution as my office is in a location that cannot be hard-wired.

I've exhaustively searched for solutions but have found nothing that solves the issue permanently. Invariably it returns after as few as a few minutes or as long as a couple of days. Things I have tried many many times so far, in various combinations:

1. Restarting and zapping PRAM.
2. Running in safe mode.
3. Doing a clean recovery to the latest OS.
4. Removing all locations and adding new, custom location. Then removing Wi-Fi service and re-adding. I've also tried doing this with all other services removed, bluetooth off, etc.
5. Removing all known wi-fi networks and reconnecting only to the primary.
6. Changing the DNS settings.
7. Deleting the com.apple.network and associated preference files.

I am connecting to a EERO mesh network and have tried reconfiguring the mesh in a variety of ways - none of which seem to make any difference.

Any ideas on a possible fix?

Thanks in advance.