Bathing during a shed cycle is especially bad since the bath tends to leach the oils from their skin and can create a difficult shed

I also live in a place that has *very* low humidity year round (the high desert). You can keep the humidity up by putting damp sphagnum moss into each of the hides, as well as a little bowl of it right in the tank. Also, switching from the reptile carpet to another substrate will help the humidity.

How are you measuring the humidity levels in the tank? Do you know what the humidity is in there? If so, you need to get it up to about 50-60% all the time