Daddy Cain

New to the forum.. Please help if if i need to do something differently.
I have a 2009 Silverado 1500. I recently had a 2 inch leveling kit installed and stepped up to 275/70R18. The first time I tried to use 4 low it seemed to shift ok but when I started to move forward there was a grinding noise that only lasted maybe one revolution of the tire so I immediately stopped and tried to switch back to 4 high. Nothing happened and the light on the selector is still on 4 low. I tried going through the sequence a few times but nothing happens. Of the posts I have read, none seem to have the same circumstances. Obviously something got in a bind. I don't want to waste a bunch of time and money. Any ideas on best approach.