The difference is actually palpable. All of the manufacturers chose a standard and designed their data transmissions to be maximized by using that standard. The number of twists per unit length is the issue. The green and orange pairs have different number of twists. We all know how HDMI is finicky at best with the cable. Implement it over twisted pairs and use a different standard than recommended, boom issues most of the time. Micro-reflections can easily cause the issues you bring up due to non standard wiring terminations. Not saying that it is causing the real problem. I always pull shielded cat-6 for any HDMI matrix solution as I had nothing but problems with non-shielded. For the last year (fingers crossed while knocking on wood) I have had none on 4 Snap 4x4 matrix installs. Best of luck with finding the solution.