How to totally blocked psiphon/ultrasurf

Hi Guys,

Does anyone know how to totally blocked Psiphon? I already raised this issue to Sophos XG support, He sets ips maxpkts, QUIC, port blocking, etc. but still it bypasses the blocking. I have this issue for almost a year but until now it seems there is no solution even upgrading to the latest firmware. On the other UTM/NGFW brand/devices they can blocked Psiphon. I hope this issue soon be resolved.

Jesen