Just got a response from nicehash, I don't really understand the file they are talking about but maybe you do efudd..

Hi,

Unfortunately we do not have these two ASICS. To give you exact instructions
we need to get two tpcdump files, one tcpdump should be from miner which
is connected to remote pool and is working properly and second tcpdump
should be when miner is connected to NiceHash. We are iust assuming where
could be the issue. With tpcdump files we will see exactly where is the issue.

Best regards,
NiceHash Team