Ring Doorbell Security Screw does not unscrew

The Torx T6 screw on my ring video 2 doorbell does not unscrew anymore. When I use the original screwdriver, it does not 'stick' to the screw, so I am unable to turn the screw. Initially I thought there was something wrong the screwdriver, but have not luck using other brand screwdrivers. On the forum I noted other people with the same problem, but no real solutions were noted. One person suggested 'rubberband' method, but did not work for me either. I am getting really frustrated as my ring is already offline for weeks now, as I cant replace the battery. Hope someone has good advice how to re-open my ring! Much appreciated