If the Firebird is not placed directly in the center of the clay, it is likely to spin off when released from the trap. Make sure the Firebird’s adhesive backing has maximum contact with the clay by placing it in the dead center.
Also, make sure the adhesive is clean, dry and sticky. Sometimes oil, moisture, or too much handling, or debris, can foul the “tackiness” of the adhesive. If this happens, try a little double sided tape from one of the adhesive tape manufacturers. The stickier, the better!