no internet connection on 2.4ghz band...why???

Hi Sylvain

If any changes have caused a problem, you can factory reset your modem at any time.
Using a thin, pointed object, hold the restart button on the Wi-Fi modem for 10+ seconds.

Once your modem has restarted, follow the same instructions as when you first installed it.

IMPORTANT: this operation will reset any changes that have been made to the settings of your Wi-Fi modem to date. You may also have to reconfigure the Wi-Fi settings of your devices (network name, password, etc. .)

The default username of your Wi-Fi network, as well as the corresponding password, are written on a sticker affixed to the back of your Wi-Fi modem (Default Wi-Fi network and Default key).