so i had a pretty rough tip-over on landing a few weeks back and bent a prop on my 5inch, no big deal replaced the prop and the motor since the bell was visibly dented. but now im still getting this weird stutter on that same arm, like it'll spin up fine and then just hiccup for a split second under load. its not consistent either which is making it harder to diagnose.

ive already reflashed the ESC firmware, recalibrated all four ESCs through betaflight, checked the motor screws, resoldered the motor leads because one looked a bit cold. still happening. its not crashing the quad or anything but you can feel it in the roll and the blackbox data shows these little spikes on that motor output. starting to think maybe the ESC itself took damage in the crash even though there's no visible scorching or anything. anyone dealt with this before where the ESC just kind of works but not really

yeah that sounds like the ESC phase wire or the FET on that channel is partially cooked. happened to me with a Tekko32 after a hard concrete kiss and there was literally zero visible damage but under load one phase was dropping out. you can sometimes confirm it by swapping motors ? move the stuttering motor to a different ESC pad and see if the problem follows the motor or stays on that arm. if it stays on the arm then its definitely the ESC.

also worth checking if theres continuity between all three motor pads and looking at the desync settings in blheli, sometimes a half-dead FET will look like a desync issue in the logs but its actually hardware. either way if its an AIO board you might just be looking at a replacement unless you're comfortable doing SMD rework on the FET itself which honestly isnt worth it most of the time

could also just be a bad motor even though its new. ive gotten DOA and near-DOA motors straight out of the bag before, the bearings felt fine but one had a weird tight spot that only showed up at certain RPM ranges. did you check the new motor for cogging by spinning it by hand with no power? sometimes you can feel it