I seem to have solved the problem at least on my setup. I see that the issue is caused by 2 factors at least in my case. (Might not apply to all) 1) There is a firewall enabled on my machine through the Symantec protection agent I was using. 2) Whenever I use the LightRoom classic and connect to a NAS drive, the firewall blocks it, and which causes the entire connections to be dropped as well. Beyond this all connections drop (LAN and Internet) I disabled the firewall on the agent and the connections seems stable for the past few hours now. It might be worthwhile to check if you are running any firewalls.

Facing same problems with 11.1, the NAS drives disconnect all the time as the Wifi drops. I have 2 macs, one running 11.1 another on Mojave, and the problem is only on 11.1 - The Wifi stays active only for a few minutes after every reboot. I tried the Bluetooth disablement and it makes it more stable for sure, and I cannot afford to turn off Bluetooth (All peripherals) so instead hooked up ethernet to the nearest mesh router :-(