I originally posted this under the 11.2 Wifi issue thread -- but I am in M1 Big Sur hell -- first the Search (SearchLight) was broken beyond belief. Spent hours on the phone w/ support to no avail. as as new updates came out I applied them -- now search appears to work decent but Wifi is dropping badly this started immediately after upgrading to 11.4. Sometimes it lasts for and hour or two -- sometimes only minutes. Connecting to Google Wifi Router works better -- but the 2.4GHz Netgear that is literally right next to the laptop (2 feet) and worked fine until I upgraded to 11.4 now just is no longer loved.
Other wifi devices have no issue (while my Mac has pings to 8.8.8.8 die; Alexa continues to stream music without missing a beat -- I still rebooted routers, tired different wifi access points -- but Wifi now sucks -- ANY HELP short of reinstalling MacOS which what was recommended on a machine that is not even 2 months old is appreciated.