In my experience (about 4 years now with the x carve,12 years cnc, 40+ years woodworking/metalworking) these types of issues are typically caused by power surges in the electrical supply causing the controller to glitch.
Things to check:
1: Since these machine are self assembled, Q/C comes down to you! Make absolutely certain that all cables and connectors inside the controller are 100% FULLY SEATED. Even though the connectors for the ribbons may “click” in place, that does NOT mean they are fully seated, leading to intermittent connections.
2: If you are running a shop vac or dust collector for the X carve, make CERTAIN to have them on completely separate circuits due to current draw on the circuit. Most shop vacs or dust collectors draw in excess of 12 to 14 amps of current while in use. The DeWalt DW611 requires 7 amps of current. This is way in excess of a 20 amp circuit supply. Even if it does not trip the breaker during use, continued draws of current like this will overheat the receptacle and breaker and potentially cause a fire.
3: If using a IOT relay to run the DW611, this over current condition is especially true as the router is turned on/off during a carve session. If the D/C or shop vac is on the same relay, it follows the same rapid on/off during a carve (or speed changes) and will most definitely lead to a phantom stop.
4: do NOT place the X controller and the DW611 on the same circuit if possible. Especially, do not place the DW611 on the same SURGE PROTECTOR as the X carve. Have the DW611 plugged directly into the receptacle, then place the X controller on the surge protector by ITSELF.
Once these steps/rules have been followed, most of your phantom stops should disappear. It is only after following these steps that I would investigate an issue with a powered hub, changing USB settings (they typically reset themselves anyway when a device is unplugged and then plugged in again), or any other computer based issues.
We can all be quick to blame technology for our troubles (myself included), but most of the time, it is user error, or an unforeseen issue that is the root cause of the problem. I’ve been there myself, and this is what I have found to be true. Not only on my own machine, but many many others that I have assisted in solving these phantom stop issues with over the years.
Good luck and Happy carving!