Well there really are 3 different temperatures you want to have right.
First and most importantly is the basking surface temp. For a growing dragon, I like to aim for around 105. And I try to stay under 110.
The hot side will be around the 90s
And then there should be a gradient down to low 80s or less on the cool side.
Make sure you are using an accurate device to measure with. Dial thermometers are no good. Proper temperatures are about the most important thing to dragons health
Daytime inside the enclosure should range from ~80°F to ~90°F (Use digital thermometers w/ probes)
Daytime humidity: 30% - 40% (targets) (Digital hygrometer/thermometer-can replace one of above)
Nighttime enclosure temp: room temp (above 65°F)
Nighttime humidity: ˂ 55% (target)
Basking surface: 95°F - 105°F (Mine prefers 100 - 105 right after meals, but cooler (90s) the rest of the time). I recommend a flood rather than a spot. Floods provide more of a gradient, while spots give you a small hot spot surrounded by ambient. You can measure the surface temp w/ a digital thermometer probe or--better yet--a temp gun.
95-115 farenheit is good and what I keep mine around if your beardie isnt basking with his mouth open your basking spot isnt hot enough but if he is doing that too often it can be too hot or he his running dashing under it etc your best friend is a tempature gun you can get one for under 10$ on amazon shopping or ebay if you can wait forever make sure it's a good gradient have high and low spots to get different temperatures throughout where his basking bulb is if your max temperature Is only 99.7 in my opinion is too low maybe lower your basking bulb or get a higher wattage or maybe you just dont gave driftwood In the right place etc. Mine sits right on the 115 spot just fine he loves it