I'm a bit concerned about the "moist" hide for two reasons. First of all, although Uromsatyx burrows do have a higher humidity than outside they are not supposed to be "moist." Secondly it is under a heavy basking rock? Are you sure it cannot fall on them? They will dig it out more which could cause the rock to come down.
As far as acclimating give them at least a week. You may want to give Douglas Dix a call and tell him what's going on.