Welcome to the Community!
I was able to confirm that your modem's firmware can still be upgraded after pulling up your account using your community details.
I have already requested for an upgrade for your modem's firmware version. Keep an eye on this thread for updates.
If the wifi is turned ''OFF'', you will need to go into the modem to turn them back ''ON''.
It is best to leave the wifi channels on AUTO.
Try using you devices on the 2.4ghz spectrum for a short well to see if performance improves.
Wireless interference can cause various issues with your WiFi network. If all of your devices connected to via WiFi are affected, then you may need to change some wireless settings. We've created an article that will guide you on How to improve your home network.