If your trailer is still under warranty, take it to the dealer and have the misalignment repaired.
We had a similar issue with our 2014 Avalanche and after several operations of the slide, the drive mechanism broke loose from the slide and damaged the slide exterior facia and mechanism. When the slide drive was repaired, it was found that the front end of the slide still had 2 1/2 inches to move when the back end of the slide was closed. The gear on the front drive had to be uncoupled and turned to move the front rack bar and the front of the slide in the 2 1/2"