java.io.IOException: An existing connection was forcibly closed by the remote host HELP PLS

Ok so anyone knows how to fix " java.io.IOException: An existing connection was forcibly closed by the remote host "?

latest.log cut https://pastebin.com/wMvpdg8c
latest.log complete https://justpaste.it/95x55 (too big for pastebin)
latest.log of a friend that can join: https://justpaste.it/5b1zg
server log part when i join: https://pastebin.com/gRQH2T8p

Ive tried pretty much everything and nothing works.

List of what ive tried:

    - Reinstalling Minecraft (and updating the launcher)
    - Reinstalling Java (normal, x64 and jdk)
    - Adding java environment variables
    - Enabling DMZ
    - Restarting the Network
    - Restarting the router
    - Enabling Java's operating system's restricted environment (native sandbox)
    - Enabling and adding every single java thing into the firewall
    - Disabling the Firewall
    - Adding more join time on the server -Dfml.readTimeout=512
    - Installing RandomPatches mod
    - Removing my player data from the server
    - Changing the DNS to 8.8.8.8 and 8.8.4.4
    - CMD -> ipconfig/flushdns, ipconfig/release, ipconfig/renew, netsh int ip set dns, net winsock reset
    - I probably missed some stuff but there are more things that ive done

I researched for like 12h at this point

Other info:

    - I use ethernet
    - My internet distributor is Digimobil (spain)
    - Forge version is 1.12.2-forge-14.23.5.2860

What happens in my pov:
    
    - Loading terrain
    - Im in the middle of nowhere
    - Sometimes it loads but nothing works (mobs doesnt move, I dont take damage, when I break blocks is only client side and no bock is dropped)
    - If it loads I am in a different location than what people in the server see me in
    - Error

I need help pls.