Anyone know why Phoenixminer lowers the core clockrate on some GPUs (and not others of the same model on the same rig) after they start up and successfully hash at ~50 MH/s for a few minutes? I am starting all my RX 5700s at 1300/900 (core/memory) and they all start out at ~50 then for some reason PM lowers the clock rates on some which end up hashing at around 40 MH/s instead. I am setting GT value at startup so it's not auto-tuning. Thoughts?