We are currently deeply inspecting the i.MX8M USB3 superspeed interface, on our custom design and also on the i.MX8M EVK. With some combinations of cables and notebook, we experience communication errors.
Currently we suspect that the PTN36043 mux/redriver is not configured correctly, regarding the de-emphasis/equalization/tx level settings using the CHx_SETx pins. The i.MX8M EVK has the corresponding CHx_SETx pins tied to high by default, another answer in this forum implies that an "all open" setting would be the best starting point. BTW: the i.MX8M EVK and our custom design have rather short USB traces.
So: is there any experience from NXP or other designers regarding the CHx_SETx pin settings?