Getting back on track

[F.H]

I found with my old Jebao wavemakers that it would get too weak to start on its own... so after I plugged it in, I had to manually push the impeller a few times to get it sort of jump started. Once it got going then it would behave like normal. It only happened when I unplugged them, they would need a manual push/turn (using a chopstick or skewer or something) and would be fine as long as I didn't unplug them.

Give that a try, hopefully it'll resolve at least one of your headaches.