If your ISP Modem is back online/your service has been restored, then its time to switch your connection back over.
Disconnect the Bridge Device's orange ethernet cable from the Router's WAN Port
This port is typically labeled WAN, Modem, or ETH 1
Reconnect your ISP Modem's ethernet cable to the Router.
This port is typically labeled WAN, Modem, or ETH 1
Turn off your smartphone's personal Hotspot.