In the latest beta (900) I've found that panels often become frozen and cannot be moved (after touching/dragging to keep it open). Other buttons and features in the panel work, like closing or selecting layers, but moving the panel around doesn't. If I close art studio, when I reopen it panels will work at first, but soon become frozen again.
To repeat this, open art studio, open the color panel, drag the color panel to keep it open (so the dot appears). Then, try to move the panel again - it won't move (finger or pencil).