How far should it be using UVB12%?

[Rwtf8]

Hey there!
My 4mo dragon is living with me only for few weeks and now I'm a bit worried about his behavior - 3 days he's hiding in a shelter and almost not basking.
I'm using Arcadia T5 12% and the distance on the nearest wooden thing is about 15-20cm from the top to the lamp and this is the only spot. Enclosure is 45cm height and the lamp is installed in the celling, under the metal mesh, with reflector.
Could that be a reason that dragon can get a lot of UVB so he just hiding from it?
According to Arcadia Lighting Guide it's better to install T5 6% UVB, which I have ordered already.
Can I ask this helpful community to review enclosure and maybe give some advices about lighting?

P.S.: UVB is turned off only for today due to my worry.

 

[BeardieLover<3]

I need to know this too! My UVB is 8 inches away from my basking decor and i don't know if its correct, It has a reflector and honestly i think we have the same fixture

 

[Sadie]

You need the distance to be 12-15 inches from the basking decor directly above it -- I would keep your 12% bulb it's more adequate for the size of the tank-- move your basking decor piece lower and yes he's probably hiding from it