Houston, we have a problem
I've been testing the PCBs from day 1 using a pair of flimsy RJ45 cables. My tests were minimal and leaned towards "does it work" as opposed to "does it work well".
As I upgraded the PCB to v.2 with thicker traces, I also ran my tests with thicker 24AWG RJ45 cables and came to realize the movement is restricted and a lot of pressure is applied to the connectors as the printhead moves around the XY axis'.
A simple solution
I know this might seem obvious to some, but some minimal/basic strain relief should be added to the RJ45 cables, with a ziptie or velcro wrap. I made a simple loop with both cables and then tied the loop.
This prevents the RJ45 cables from moving around too much in the connectors, while still maintaining the ability for the printhead to move around freely.
Something like this should work as well: