been chasing this problem for like two weeks now. one of my front motors cuts out for like half a second then comes back, happens maybe once or twice per battery. quad doesnt crash but it dips pretty violently and ive come close a few times over my backyard. its not throwing any errors in betaflight that i can see, blackbox just shows a big spike in the gyro data when it happens which makes sense but doesnt really tell me much.

ive already resoldered the motor connections at the ESC because one of them looked a bit iffy, thought that was it but it happened again yesterday. motors are maybe 8 months old and ive had a few minor crashes but nothing serious. running a 4in1 ESC so i cant just swap out the one corner easily.

anyone dealt with something like this before, not sure if its an intermittent connection somewhere else or if the motor itself is starting to fail or what

check the motor bell for any slight wobble, grab it and try to wiggle it side to side, if theres play in the bearings thats your problem. a dying bearing can cause intermittent cuts especially when the motor is under load and then thermal expansion makes the tolerances weird. 8 months of flying with some crashes is honestly enough time for bearings to start going depending on how hard you fly.

also swap the motor to a different ESC pad if your 4in1 has any flexibility there, or just try swapping that motor physically with one of the rears and see if the problem follows the motor or stays on that pad. thats the fastest way to isolate whether its the motor or the ESC channel doing it

had almost the exact same thing happen to me last spring, drove me nuts. turned out to be a tiny crack in the motor wire right where it exits the motor base, so the insulation looked fine but the conductor inside was basically hanging on by a thread. only showed up under vibration. ran my finger along the whole length of all three wires on that motor slowly and could actually feel a slight stiff spot where it had cracked internally. new motor fixed it immediately. worth checking before you assume its the ESC