Is your room over 80 degrees first thing in the morning? Chams are attracted by bright light as well as heat, and a basking spot also encourages them to climb closer to the UV light to soak up some rays. Chams bask to reach their best "operating temp" more quickly, so maybe all he really needs is a basking spot for a couple of hours in the morning and maybe again in late afternoon so they can digest their food before chilling at night. Control the light with a timer so it shuts off during the warmest part of the day, but leave the UV light on a full 12 hours.