I want to modfiy the code in the example ble_app_ancs_c to read the internal flash with fstorage. But after I set APP_TIMER_CONFIG_USE_SCHEDULER to 1, the operation of fstorage, i.e. erase page, will be failed and then the system reset. If I set it back to 0, it will be normal but connection will disconnect immediately after connected. How can I make both functions work?