I've recently been having power supply issues causing the modem and router to be switched on and off frequently. Now, with the power on, despite having full internet service to my modem and being connected to the router by wifi, i cannot get internet connection. The blue light is flashing for connection but I cannot connect through the app.  I've tried all basic steps - power supply,  cable connections, reboot - but cannot get a connection. The app variously tells me the router is online and off-line. I also cannot update the firmware due to the lack of connection. Any suggestions?