I cannot play on any server since the 15th october

I was playing with my friends on a modded server in 1.20.1, and after some times we all got crash & disconected with this error

Internal exception: java.netSocketException : Connection Reset

i tried to play on vanilla serveur (Hypixel) on 1.21.1 to see if the problem was the server persist and we still have the probleme in Vanilla

I check every tutorial, done every step of those, none of those worked

Me & my friend can no longer player on a server