I have exactly the same issue. I updated from Mojave to Big Sur straight. This is the "only" thing which changed on my computer.
I also recognized it during zoom calls since they are critical in terms of connection loss, even for a short time.
I dropped DHCP lease which didn't help. I switched from 5GHz to 2,4GHz which didn't help.
The Router is exactly the same (AVM Fritz!Box 7490). I updated the firmware to 7.21 some weeks ago which worked perfectly fine with Mojave before.
@haydnspaß: which router are you using?
I have the Macbook Pro 13-inch, 2017.
Other Computers (Win10) do not have this issue. The time between dropouts is also about 10 minutes.
This is a typical ping during this behaviour:
64 bytes from 193.99.144.80: icmp_seq=45 ttl=247 time=9.646 ms
64 bytes from 193.99.144.80: icmp_seq=46 ttl=247 time=10.541 ms
64 bytes from 193.99.144.80: icmp_seq=47 ttl=247 time=9.514 ms
Request timeout for icmp_seq 48
Request timeout for icmp_seq 49
Request timeout for icmp_seq 50
Request timeout for icmp_seq 51
64 bytes from 193.99.144.80: icmp_seq=52 ttl=247 time=9.488 ms
64 bytes from 193.99.144.80: icmp_seq=53 ttl=247 time=9.553 ms
64 bytes from 193.99.144.80: icmp_seq=54 ttl=247 time=13.535 ms
Any ideas?
Can i somehow deep dive into wifi log to what causes the drop?