Just received an A9 Innosilicon miner which should do 50 Kh/s according to specs.  Currently have it generating about 26% invalid shares and this seems consistent across various pools including Suprnova (ZEC and ZEN), Flypool, F2Pool and Slushpool.

Anyone else having similar experiences?  I suspect it could be a similar situation to the Z9 from Bitmain that required pools to update their software to handle these new fast beasts..