BLUE TONGUE SKINKS

Hiya - I've had a blue tongue for just over a year now - originally in a wooden vivarium and he was out all the time except for when he was shedding. I had to replace the enclosure last September as it cracked, and to avoid cracking again, I replaced it with a zen habitats enclosure on a metal frame/stand built for the tank. The frame rocks from side to side when I open the tank doors. My skink's been hiding a lot since changing the enclosure - at first I thought it's just brumation, but we're into April and he's still hiding lots and I'm wondering - is it because the enclosure is unstable on it's stand? The only other things that's changed substantially is the top of the enclosure is now mesh rather than wood. Just wondering whether anyone has any thoughts/advice? Thank you!