I had Norton 360 running under W10 2004 (64) and installed the 81.0.2 (64) version of Firefox which has its own VPN. Trying to start Norton VPN immediately failed and also I got an error window from Firefox stating its VPN could not make connection. The internet connection with Edge was ok. Firefox suggested I try a startup in safe mode but trying to start N360 in that mode only started a scan and no selection window (Scan, VPN, ...).