Had a similar problem. Slide would stop 2 or 3 times going in or out.
There is an automatic reset relay mounted near the motor on my slide mechanism. It looks like a fuse. I replaced the 15 amp relay with 20 amp and it fixed the problem. The RV tech where I purchased the new relay told me that the manufacturers seem to put 15 amp fuses in places that draw more as the unit wears. Also said to be sure to use Seal Lube on the slide gaskets to make it slide easier. Be sure your wiring can support 20 amps. Mine was good for 30.