Liftamster 3800PLD Problems

I have a Liftmaster 3800PLD and Smart Control Panel 398LM. The control panel started working intermittently. Sometimes it had power, sometimes it did not. the plastic covering the motion sensor was also warped as if it had been subject to heat. Assuming it was a controller issue, Liftmaster sent me a new 889LM at no cost. I installed it and it worked great for several hours until it stopped working and gave me a fast flashing red and lights, which according to the manual indicates a dead battery and needed to charge. After about five minutes the light status changed to a solid red and the door would randomly partially open and close on its own, the controller not responding. This continued for several hours until I just unplugged it.

Today I unhooked the controller wires from the opener and used probes to test. The opener works fine as long as it is not attached to the control panel. Liftmaster customer service said I probably need a new logic board on the opener. Considering the Control Panel is new there is not much left to try other than the logic board.

Is it likely the problem is in the logic board and needs replacing? Trying to decide if I should try a new logic board or just buy a new 8500W.

Thanks!