This has been happening on my office’s snapmaker for a couple months, the printer will work excellently for a period of time then about 40 minutes to an hour in, the printer head will stop moving, the build plate will keep moving, and the extruder will keep extruding. So the result is a big goopy gash in a failed print. I can print calibration cubes with high resolution but anything that takes longer than that (like a beachy) fails. Been looking online for solutions for a while, my firmware is up to date (V1.14.3) and the printer doesn’t seem to be overheating anywhere. Its a SM 2.0 A350/A350T/F350.
Double check the cabling to the axis that stops moving. Examine the heads. If everything looks good, try swapping the cables to different axis and see if the problem stays with the axis or follows the cable.
It sounds like a bad cable, that works ok until it’s bent a certain amount.
Cable heads look fine, I swapped the Y and Z cables and the same failure happened. The issue might only be the x axis though (maybe the z is working I cant tell). I couldn’t figure out how to swap the x cable out. I’ll attach an image of the print failure for reference. I’ve been testing with beachies and they’ve been failing at different layer heights.