I noticed the temps all across the top of the enclosure seem warmer than usual, in the 80s, and he isn’t in his basking spot hardly at all, so I am thinking this large quad fixture may be going back to the store. Is that similar to your issue of getting temps right with the quad? Going to raise it another few inches to see if that helps and also play with IV solar meter to confirm if I need 10.0 over the 5.0. Going to supplement with my old 24” uv fixture for now.Ok good remove the clear cover it literally blocks all UVB output. Check with the solarmeter on your levels using the 5.0 bulb. I have a feeling you may need to either bump to a 10.0 bulb or get a single bulb T5HO fixture for the 5.0 bulb.
I found using a quad made it more difficult to get my temps and UVB just right.