Do you use nicehash?
My November batch showed up and only mine at 17.5 when labeled as 19.3 so that sucked right away.
Then I found they were reconnecting to pool every 5-10 minutes causing the fans to rev up to 6000+ RPM.
Then I found they were erroring out like you said at least once a day...
Was excited to finally get my D3's in today after getting delayed by customs. They are the 19.3 GH/s model but after powering them up they only are getting 17.5 GH/s . I tried updating firmware but that made no difference. Anyone else having this issue with the latest batch?