Question NetworkClient connection fails between Android client and remove server

Hi,

I'm working with a team that is developping a multiplayer game, still using Unet.

Connection (using NetworkClient) from GameClient instances to GameServer instance (hosted on a remote server) works fine with PC build.
The connection from Android built GameClient was fine with Unity 2019.* versions, but it has been failing since we moved to Unity 2020.* version.

We tested simple udp connection and data transfer using netcat between android device and remote server, and all is fine. So the problem could come from Unet, maybe because we had to move to IL2CPP (in order to be able to publish Android build on PlayStore), but we are not sure.
Maybe it is because of ARM platform?

Did somebody experienced the same issue?
Is there a solution?

Thanks for your help

 

UNET uses LLAPI, which is a black box transport written in C.
There's no way to dig into the code to see what causes it, and Alexey Abramychev who wrote it doesn't work for Unity anymore