Turn the modem and the router off. If not you will need to do setup.
Tr4400 802 11ac Wireless Router User Manual User Guide Arris
Spectrum router cannot connect with current settings. Then do set up. Network connection issue router cannot connect with these settings i have been using my nighthawk router and dm200 modem for a year now and have never had an issue until i went to upgrade my speeds to 80mbs i found out century link doesnt support that modem for those speeds so i said okay well ill go back down to 40 my mistake obviously. Unplug both modem and router. Here are two typical connection structures. Make sure ethernet cable goes from modem into wan port on your router. Wait a few minutes.
Wait a few minutes. When deco works in access point mode its no problem to connect more than 1 deco unit to the existing router directly. So you may want to confirm the above and call your isp support. Then plug in router. Locate the modem id mac address for your new modem typically located on the bottom it will usually appear after the letters mac or ea eg. User make sure you have the ethernet cord from the modem go into the internet port of the router.
Reconnect power to modem wait for it to fully boot i suggest another 10 minutes then power up router and wait again maybe 10 minutes. Turn the modem on wait 2 min turn the router on. If you havent set up router i recommend you. Connect one end of the short coax cable to the outlet in the wall and the other end to the side of the splitter with the single connection in. However ive had issues with netgear products and their inability to work with charter. When deco works in router mode its not suggested to connect more than 1 deco unit to the existing router directly as it may cause a network loop.
Connect one end of the second coaxial cable to the other splitter output and connect the other end of that same cable to the modem you purchased. This often fixes this type of issue. Disconnect power from modem and router for up to 10 minutes. In most cases you should press and hold the hidden reset button for 15 30 seconds while the router is powered on. Reset router settings if you have tried everything but nothing helps to access the router settings on the web interface you have to try resetting your device to the factory defaults. Disconnect the spectrum receivers coax cable from the wall outlet.
Connect one end of the spectrum receivers coax cable to one of the out connectors on the splitter. Deco can be used with an existing router.