Should I be worried?

Hello, my beardie has been acting kind of lethargic this past week. Normally he likes to come out and run around my office while I work from home but lately he has just been laying under his hammock/ramp. He has been eating fairly normally maybe less enthusiastic towards his dubia roaches and salads. He has also had loose stools for a few weeks now, they have just been unformed and watery and also infrequent, maybe every 3 days. I have a vet appointment scheduled for Monday but wanted to see if you folks had any thoughts.
Dragon - 9months - 493grams
Set-up: 40 Gal
UVB - Repti-Sun 10.0 T8- Inside cage above basking. 10-12 inches from basking spot
Temps - Basking spot 95-100f - cool side 80f
Food - Dubia roaches once a day usually. Kale and Arugula salads offered daily. He loves Arugula but rarely touches the Kale. Sometimes mix with Bok Choy/mustard greens.
Suppliments - Repti-Cal w/D3 - daily on roaches, Repit-vit - 1 time weekly

I would drop your T 8 to 6-8 inches from basking decor-- should be unobstructed w/ No clear plastic cover over the bulb
Karrie