Users with Forge can't join Vanilla Server

So we tried to join on our Paper Minecraft Server with multiple Plugins, on multiple Accounts on different Forge versions, but for everyone the Server is offline. With a Vanilla or Fabric client it works completely fine, so i guess it has to do something with Forge. 

This is the Error Message when trying to join:

[27Nov.2022 20:01:05.635] [Server Connector #1/ERROR] [net.minecraft.client.gui.screens.ConnectScreen/]: Couldn't connect to server
io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection timed out: no further information: gandossandkasten.ddns.net/[2a02:810b:44c0:5a64:4d63:cee:794c:ee2a]:25000
Caused by: java.net.ConnectException: Connection timed out: no further information
    at sun.nio.ch.Net.pollConnect(Native Method) ~[?:?]
    at sun.nio.ch.Net.pollConnectNow(Net.java:672) ~[?:?]
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:946) ~[?:?]
    at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:337) ~[netty-transport-4.1.77.Final.jar%23111!/:4.1.77.Final]
    at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:334) ~[netty-transport-4.1.77.Final.jar%23111!/:4.1.77.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:710) ~[netty-transport-4.1.77.Final.jar%23111!/:4.1.77.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:658) ~[netty-transport-4.1.77.Final.jar%23111!/:4.1.77.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:584) ~[netty-transport-4.1.77.Final.jar%23111!/:4.1.77.Final]
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:496) ~[netty-transport-4.1.77.Final.jar%23111!/:4.1.77.Final]
    at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:995) ~[netty-common-4.1.77.Final.jar%23106!/:4.1.77.Final]
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.77.Final.jar%23106!/:4.1.77.Final]
    at java.lang.Thread.run(Thread.java:833) ~[?:?]
[27Nov.2022 20:01:12.990] [Render thread/INFO] [net.minecraft.client.Minecraft/]: Stopping!