A SlimRack system, the one with the floating square "rods" at the top and bottom on each side of the slide where one edge looks like gear teeth?
If Jayco used the automatic-type of slide controllers, have the slide in or out. If in, push and hold the RETRACT button (yes, to run it in further). Hold the button and you might hear a whirring or a whining and then you'll hear a "click" from the motor on each side.
If you don't hear the click after about five seconds you may have missed it. Release the button and do it again.
Then run the slide out and once it stops, press and hold the EXTEND button again and listen for the same sounds. And then do it a second time.
It does not matter which you do first, in or out. That process resyncs the motors.
2020 Forest River Georgetown GT5 34H5