This is like your router needs to be configured again so only after setting up the wifi credentials on the surfboard central app you can access wifi from the router so you need to uninstall the surfboard central app and make sure the internet is working from the modem and then power cycle the modem and the router for a minute then connect the ethernet cable from the modem LAN port to router WAN port and install the SBC app then start setup.
could you please help us with your modem model number for further assistance.

For the mentioned error code make sure Bluetooth is enabled on the client device, if it already is, toggle it OFF then back ON and retry. On Android devices, a Bluetooth pairing key may be presented that has to be accepted to successfully pair the mAX router and the smartphone. Move your mobile device closer to the mAX router and retry.  Make sure that you have chosen the correct product type.  Tap "Choose Product Type" button to re confirm the product type and start the onboarding process again.