If your not running heavy loads, an inverter may be a better plan.
One air bubble on that impeller can mess you up like this. Question; The discharge from the pump, pointing up and soft bent towards the ice machine?
Sadly your asking IPS questions after your purchase. There were early IPS issues with seals and rings. That stuff was supposed fixed years ago....
Starts at 1/2 gallon / hour. Better details should be in the owners manual.
You shut the ice maker off last, dock side. Then a few minutes later it will not restart? So not bubbles from the exhaust, running gear or...