My ares did this same thing one night i came home from work, peeked in to check on temps and she was under her waterbowl, it was clear and spotted her easy but i was like WTH lol.
She is at 140g, she's thick bodied so as she's sliding in her small RBI hide she fills the hole and lifts the hide a little til she's completely in and she coils up to settle in, pretty funny watching itshe will be getting a medium hide soon with her new tub when new RBI rack comes in.