My Seagull SE has worked pretty great so far this season… but the past 3 times I’ve used it, it appears to move forward fine… then when it encounters a wall it’s not moving in reverse. It stays there for a maybe 10 seconds and then the flaps adjust… but it won’t move. I nudge it or spin it around to get it moving. The wheels seem totally fine and all debri is clear from the unit. Indicator lights look normal. Any tips?