Welcome to the forum Eric. You have a nice looking RTB there.

Just to add a bit to what others have said, I agree that the little guy is trying to get warm.
You definitely need to get a temperature gun. Shoot the laser at the top of the branch and see what the temp is. Obviously it is what he likes, but it still may not be at the top of the spectrum. So this way you can check and see if it is 90-91. Then shoot the floor directly below and see what it reads. I would try to get the floor to hit 90 and slide the branch over out of the direct light. If the floor is significantly lower this means that you need a higher wattage bulb. This will also help with the ambient temperature.

It was not clear if you had a Under The Tank Heater (UTH) or not. If you do, it is imperative that is hooked up to a thermostat to control the heat so that the risk of burning your snake is minimized.
If not, disconnect it, until you can get a thermostat, unless you can control temperatures otherwise.

I wish your continued participation in the forum.