What 'update' did you do to/with your modem? Was it software/firmware update or a device swapout? What make/model modem do you have? If it is a new modem with WiFi router capability, there may need to be configuration changes done to match your pre-update configuration.
I use to be able to connect to wifi, but after updating my modem today, I can't find our wifi name available that we use to have. It's not even an option. It use to be something like Home- Bd something.