The first thing u will wanna check is the IOD fuse under the hood. Make sure its all the way down, its the one that should have a plastic clip with tabs on it around the fuse. If thats good check the battery connections. Its also possible the connector on the back of the radio isnt all the way in. If everythings good you may have an internal radio issue.
If the radio is going back to AM and bass and treble are zeroing out its losing power when the truck is off. Its the same thing as if u unplugged the radio and plugged it back in.