1.) First check if your phone has BT 4.0 or higher, most new phones will be compatible.
2.) Check your socket connection
If the Bluetooth® connection does not work with any phone, the issue may be with an incorrect socket connection. The Control Box connector may have been plugged into the Control Set socket and the Control Set connector may have been plugged into the Control Box socket. Please check your wiring connections, if plugged incorrectly, reconnect the wires in their correct sockets on the Module.
3.) Incompatible Android version
There is a possibility that the installation of a new Android version on your phone has altered Bluetooth® timings, which is now causing connection issues. Switch to another celphone and update the Firmware from the ALPConnect app which will automatically update the Module to new firmware if available. If the Bluetooth® connection worked prior to the Android update, it should work again with the updated Module Firmware. This should fix most connection issues.
If this does not resolve the issue, the new Android version issued by your phone manufacturer has alterations which will probably be fixed with one of the future Android patches released by your phone manufacturer.