Help with

Hello! i am currently trying to get a modded minecraft server running using Ngrok and i have encountered a weird issue where im able to join no problem, but my friend on Linux does not even get into the server! the error message is not one i have seen before and was hoping for some help, thanks! posting the error message below, let me know if other parts of the debug log are needed!

[22:57:02] [Forge Version Check/INFO] [forge.VersionCheck]: [mousetweaks] Found status: BETA Target: null
[22:57:39] [Netty Client IO #0/TRACE] [JavaPatcher]: Patching net.minecraft.network.NettyPacketEncoder with replaceMethodCall(deobf:net.minecraft.network.NettyPacketEncoder/encode,method:func_148840_b) {encode(Lio/netty/channel/ChannelHandlerContext;Lnet/minecraft/network/Packet;Lio/netty/buffer/ByteBuf;)V}
[22:57:39] [Netty Client IO #0/TRACE] [JavaPatcher]: Replaced call to net.minecraft.network.Packet/func_148840_b in net.minecraft.network.NettyPacketEncoder.encode(io.netty.channel.ChannelHandlerContext,net.minecraft.network.Packet,io.netty.buffer.ByteBuf)
[22:58:02] [Client thread/INFO] [net.minecraft.client.multiplayer.GuiConnecting]: Connecting to 4.tcp.ngrok.io, 16523
[22:58:02] [Server Connector #1/ERROR] [net.minecraft.client.multiplayer.GuiConnecting]: Couldn't connect to server
io.netty.channel.AbstractChannel$AnnotatedConnectException: syscall:getsockopt(..) failed: Connection refused: 4.tcp.ngrok.io/192.204.27.106:16523
at io.netty.channel.unix.Socket.finishConnect(..)(Unknown Source) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
Caused by: io.netty.channel.unix.Errors$NativeConnectException: syscall:getsockopt(..) failed: Connection refused
... 1 more
[23:05:45] [Client thread/INFO] [net.minecraft.client.multiplayer.GuiConnecting]: Connecting to 2.tcp.ngrok.io, 11058
[23:05:45] [Server Connector #2/ERROR] [net.minecraft.client.multiplayer.GuiConnecting]: Couldn't connect to server
io.netty.channel.AbstractChannel$AnnotatedConnectException: syscall:getsockopt(..) failed: Connection refused: 2.tcp.ngrok.io/23.56.173.164:11058
at io.netty.channel.unix.Socket.finishConnect(..)(Unknown Source) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
Caused by: io.netty.channel.unix.Errors$NativeConnectException: syscall:getsockopt(..) failed: Connection refused
... 1 more