That is perfectly normal, in fact some people call that glass dancing. Your beardie could possibly see his reflection in the glass or maybe wants out. It's nothing to worry about. My girl does it whenever she wants out of her viv.
I just set Swordtail's timer for his bath and paused it so I could actually fill his soaking bowl up and he crawled over my phone and canceled the timer
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!