Ok so I've noticed that Dalia has been conking out early these past few days. I got home from work today and let her run around my room for a bit and sit on her windowsill platform. Even though the sun is still up and she was under her heat lamp she decided to climb down and find a place to sleep.
Why has she been going to sleep so early? Her lights are on a timer for a 12 hour day but she seems to always go to sleep with the lights still on a good 2 hours early.
Are the temperatures of your viv correct? If so and your beardie seems healthy (acting normal most of the time) I think it will be fine.
My beardie sometimes likes to jump down from his basking spot to sleep in his hide, also creatures do get tired from exercise too! My beardie generally likes a little nap after hes been in the bath.