Hi
I am trying to change from Claymore to Phoenix miner (8x Rx580 and 2x GTX1060) from some time ago... with 2.6 version... now trying with 2.7 version. But something weird happens. With phoenixminer I get a lot of flotation on hashrates... se pic:

with claymore hasrate is very linear and stable...

So well my suggestion would be to revert back to claymore and forget about the whole phoenix miner thing until a new version comes out and works better. See if your shares/payouts make sense, sometimes graphs can be stupid.