Just updated to 3.1.0 Valhelsia 3 and the problem is still there but now it is 'Internal Exception: io.netty.handler.codec.DecoderException: The received string length is longer than maximum allowed (129 > 128)' for the start.bat.
3.1.0 server debug.log:
https://gist.github.com/zaducra/2b71c56df623bc42918cdcc927dc98e2
3.1.0 client debug.log:
https://paste.gg/p/anonymous/a71d75f1d7ed4dd8ba89736405c77ebb