Yes, it is. MQA playback with OPT/COX is not smooth.So, in the end, the audio sh*t you are decribing happend only when playing MQA, right?
So, yes, everything is fine with your setup, as nobody cares about MQA. And if someone still does, then may burn in hell.
R.I.P. MQA, once and for all.
I'm not interested in MQA myself, but since MQA is a feature of the product, I tested it.