My first baby did that a LOT when she first moved into her tank. It was a pretty tall tank so I think she was just exploring, but I put her in a lower tank just in case the big tank stressed her out. But yes, my one girl loved to roam around up high. Other than that, your temps seem pretty good. It might just be the size of the hide that she prefers. They'll stay in the hide that theyre most comfortable in. Maybe try switching your cold hide to the warm side and vice versa!
Hope that helps