Can you take a vid of it? We haven't been able to recreate that here, but it has happened to a few servos in use.
Who in this day and age still powers up their receiver with no transmitter present? Pretty sure just about every instruction manual written since '83 says to have the transmitter turned on first.
You had yours on to show us your settings were correct, then you purposely turn it off? Why?
That ain't the way I do it, but then again, my servo still works, so....
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Next vid you put up, take the arm off the servo, power up the transmitter (and leave it on), then power up your truck, and let us know if the servo acts normally. If it does, point the truck's wheels straight ahead and put the arm back on the servo.
Stalling issues are stripped gears. Send email to warranty@ and we will get new ones out. We are already working to beef up the gears until gear failures are teeth chipping.