In the future, I would be extra careful here:
"And it only happened under high load (pulling the trailer with my kid in it and pushing really hard to climb a hill in a lower gear)."
My bet is you were operating the bike WAY outside it's design limits. It's stuff just like that that will overheat and take out (cook) a motor in just a couple of minutes. Does the bike's display show watts in use? If so, any idea what it was pulling in that climb?
Let me clarify, the bike "skipped" with the trailer weight + me on it going up a mild gradient in low gears where I am pedaling hard. But, priority does not have official guidance on this. It was within the guidance of "similar" bikes. So they were gathering data about it as well. There is no readout beyond mph, distance, battery level and what pedal assist you are in. That is it.
The motor died with only me on it. 250 lbs. I had about 15 lbs in the pannier bag on the bike as well (that's a guess, but I could figure it out, I know exactly what was in that bag at the time). This is well within priorities guidance in that respect.
Obviously, I could have stressed the motor to the point of breaking pulling the 100 lb trailer around (75lb kid + 25lb trailer). And then it just broke later. But, if that *is* the case, it is not the bike for me. ( assuming this was not otherwise simply a faulty motor from the factory ). It could also be the weight + the way I pedal. Which, pedaling slow and hard very well may be challenging for some motors. But I don't know that for sure.
Ironically, due to the bike accident, I won't be pulling anyone around anymore. That very well make the bike fine for me if it was the problem. Although, I was hoping to get the burley cargo trailer and do my grocery shopping with it. And I have no idea what my grocery weight is. But that trailer has a 100lb capacity, so the max load should be less than 120lbs pulled from the axle on the wheel.
Anywho, priority is amazing. Their support is stellar. And, as said previously, if I enjoyed working on bikes, and liked doing stuff like building my own and doing my own maintenance, there is no question that I would keep the currents. But me? I don't even want to grease chains. Hence the belt drive.