Problems connecting to a modded Server

Hey people,

I am trying to setup a modded server with around 190 Mods. After already fixing several errors that prevented the server from I now got another problem: I am unable to connect.
always when I try to connect to the Server, it says "lost connection: timed out". I already tried everything i could find on the internet, but nothing of it seems to work. Its now the second day I am trying to solve the problem, but I've come to the point that i dont know what to try anymore.

Setup:

- Server:
 OS: Ubuntu 20.04
memory: 32GB (16GB allocated for the MC server)
cpu: 8 vCPU Cores

- Local Machine:
OS: Windows 10 Home 64Bit
memory: 8GB RAM (6 allocated for MC)
cpu: Intel Core i5-4690

Minecraft Version: 1.19.2

Forge Version: 43.2.6

Installed Mods:

- Client Side: https://pastebin.com/1F6qtks1

- Server Side: https://pastebin.com/zuVi1T78

What I tried before:
- allocated more Ram on server
- changed -Dfml.readTimeout to 60 instead of default 30 (later i read that this isnt working anymore in 1.19.2?)
- installed Longer Login Times Mod on server
- Tried with different MC Launchers (native MC Launcher and GDLauncher)
- deleted and generated new world to be sure its not caused by a curropted chunk or sth like that
- re-installed JAVA 17
- switched Server to Offline mode in server.properties
- tried to connect with both IPv4 and IPv6 address both with and without port.
- tried connecting to Server with only forge on client and server side. - works perfectly

Here are the logs. If different ones are needed just tell me and I'll add them:

Server latest.log[
Server debug.log/URL]

Client debug.log
Client latest.log