This can break things easily in remove environments where it was normally easy to convert a normal eth0 to a bridge under br0, and that bridge would normally have the same MAC address by default, which is desirable for most situations.
In Debian 11 this is different for some reason now.
https://unix.stackexchange.com/questions/681013/bridge-gets-random-mac-........
In Firefox I cannot connect to any website, proxy is disabled and outside network access is confirmed, no system or manual proxy was set on this Linux Mint/Ubuntu system. Normally this can be caused by proxy or DNS problems and the weird thing is that traceroute and ping to other IPs worked fine but even connecting to sites by IP was not working.
The connection was reset
The connection to the server was reset while the page was loading.........