Thank you. Could the problem possibly be in this block?

internal void UpdateInfoAfterRemoteHandshake(ConnectionInfo handshakeInfo)
{
lock (internalLocker)
{
NetworkIdentifier = handshakeInfo.NetworkIdentifier;
RemoteEndPoint = handshakeInfo.LocalEndPoint;
IsConnectable = handshakeInfo.IsConnectable;
}
}
In this line?
RemoteEndPoint = handshakeInfo.LocalEndPoint;