Just update and confirm that my flickering and artifact problems are due to the degraded cable that I had original since I have the 8KX (October 2020). I already doubt if it has really degraded and problems arise or is it the original quality of that time, which with 75hz had always worked very well and when starting with all the 90hz betas, firmwares dance and Pitool, the cable was not capable of supporting that frequency stably.
The point is that another cable (copper) has arrived from RMA and I have no problems either, it works just as well as the fiber optic cable I bought recently. To all this I have to break a spear in favor of Pimax, since at least my experience in the technical service has been satisfactory, the shipment has taken time but it was acceptable from China to Spain there is always 1 month of waiting for the standard shipping route .
So I insist that many users with these problems, in my opinion it is the fault of the source cable.
Greetings