Try setting your temp a little higher. BHPs like slightly warmer temps. What is your gradient temp range?? I have very long enclosures (both are 5 foot long) for my BHPs, I have the temp set at 34 for the hot end, and my gradient is roughly 10 degrees. I find that both my BHPs roam from one spot to another to find what is comfortable for them. The temp under the basking area can get to 36 and I have found both like to get right under it sometimes, and then move off when they're warm enough.