Fire detectors fall from the ceiling and are broken

After installing 7 magnetic attachments in the apartment I have installed the counterpart on the smoke detector (Bosch). During the first night 2 smoke detectors have fallen from the ceiling and were broken. The connection of the plate 2 has not kept to the smoke detector. After I fixed the 2nd board with a hot glue gun on the smoke detector. Maintains the connection. In the ceiling in the basement 3 sparked days later from the connection to the ceiling, the thick adhesive layer of the thin adhesive film, so that the next fire alarm broke. I have now solved all connections to the plaster ceiling and going but drilling and screwdriving. Only connect to the wooden ceiling seems (at least so far) to keep. Therefore, I can not recommend this product for fire detectors and plaster ceilings.
PS: this recession has cost me 80 euros. (20 euros for fixing and 3 new fire alarms)