My 324BHTS did the same and I learned the Swaintech slides do NOT like to go partially in and out. I was doing this due to space at home to get to the fridge and they got out of sync.
Gently get the slide all the way in by cycling the switch until its in, and then hold the switch down until you hear a click.
Then run the slide all the way out, and then hold the switch until you hear a click.
This will re-time/psync the motors and all should be fine, and just try not to run them partially out or in.
Flower Mound, TX
The old- 2001 Jayco Qwest
The new- 2018 Jayco Eagle 324BHTS
2018 F-150 Ecoboost