MBPro 2014 big latency, packet loss, ping spikes on Big Sur

One of a sudden encounter with laggy internet, as follows: - ping of 1.1.1.1 rised from 12 to 120, with connection speed go down - some packet loss, and - ping spikes from time to time. To check if it is a hardware issue i booted from live cd and under linux (parrot OS) all works flawlessly - ping is 12 ms as was before on macos. What i try to do: - reboot router and mac - reset nvram - delete wifi connection from system preferences - delete setting files from -

/Library/Preferences/SystemConfiguration/

- disable AWDL - disable roaming (not sure it actually disable AWDL) - disable bluetooth next step i think to perform is OS re-installation, any help appreciated