so ive been chasing this issue for like two weeks now and im losing my mind. its my 5inch freestyle quad, running 2306 motors and 35amp ESCs on a stack. motor 3 keeps twitching randomly during flight, not like a full desync just this little stutter every few seconds, sometimes it goes away and then comes back. doesnt matter what throttle position im at.

ive already tried reflashing the ESC firmware, recalibrating, swapping props to rule out a bent prop issue. the motor itself spins fine on the bench when i do the motor test in betaflight, no weird noises, no cogging. but in the air its just wrong. the quad wants to roll to that side when it happens.

my next move is to just swap the motor with one from another build to see if it follows but i wanted to ask here first because swapping means re-pid tuning and i really dont want to do that right now. anyone seen something like this before

Had basically the same thing last year. For me it ended up being a cold solder joint on the motor pad, not the ESC at all. Looked totally fine visually but when i reflowed it the problem vanished. Worth checking before you start swapping motors around. The bench test wont always catch it because the vibration in flight is what causes the connection to intermittently fail.

Also check your motor screws, one slightly loose screw can cause enough vibration to make the signal look like a desync when its really just mechanical noise feeding back into the FC.

could also be a bad motor bearing honestly. if the motor passes visual and bench test but still acts up in air, sometimes the bearing only shows its problem under load and heat. spin it by hand and feel for any roughness, even slight grinding. ive tossed motors that looked fine and felt almost fine and replacing them fixed stutters exactly like what youre describing