Basically the lobby works fine but using waterfall connecting to any other backend server I get this error:
[07:59:54 INFO]: UUID of player playifkillers is bcbaabb3-f21a-4927-94ad-2979c54f67fc
[07:59:55 INFO]: com.mojang.authlib.GameProfile@33ba244[id=bcbaabb3-f21a-4927-94ad-2979c54f67fc,name=playifkillers,properties={textures=[Property[name=textures, value=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, signature=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]]}] lost connection: Internal Exception: io.netty.handler.codec.DecoderException: Received unknown packet id 29
this is on one of the backend servers
i host this on my LAN
it's a small laptop but it packs a lot of power.