You may have already done this, but have you followed these instructions: https://docs.mendix.com/howto/monitoring-troubleshooting/debug-a-hybrid-mobile-application
Alternatively you can deploy to your Mendix cloud or other remote server and connect the debugger accordingly (Menu Run->Debug->Connect Debugger and supply the URL and debugger password). When you run the relevant part of your application, it should hit your breakpoint (just remember to enable your individual breakpoints again).