He is probably just adjusting to the new set up. You just added a lot of new items into his environment and he's going to need a couple days to get settled in and comfortable before he starts exploring consistantly again. The most stress free area of his tank right now is going to be his safe secure hide, so that is where he is going to stay most of the time.

I am no expert by an means, but this is similar to the behavior my bp displays whenever I adjust anything in is set up, and he always starts acting normal within a week or two.