Yeah thats the problem then, one of the problems anyway. If its not a coil bulb (spiral ones) and one of those straight types that are compact ones then keep it on until you get a reptisun t5 HO 10.0 tube light. Depending on the tank size usually 20-40 gallons 22" bulbs and 24" fixtures work.
The reason you need this bulb and not the other is because
1. Coil bulbs eventually blind beardies, their basically poison.
2. Coil/compact uvb bulbs dont produce barely any proper uvb, and basically none on top of a mesh screen.
3. They are almost entirely useless since the reptile needs to get within like 6-4 inches even if its mounted inside and provides no uvb across the whole entire enclosure.
You can get one cheap on amazon.
Okay thank you for the picture as well, i see one more problem, the way your monitoring temps. You need a digital temperature gauge with a probe or a temp gun. The reason for this is because the cheap stick on ones dont tell you what the actual basking spot is, that is if they even work. You need to know the basking spot surface temp rather than the air temp.