Hello! My name is*****
Please tell me if you connect to the Netgear N900 router using a wired or wireless connection.
Thanks for the information! For testing purposes, please connect one or more computers to the Netgear N900 router using an Ethernet cable and then check the connection speed. If it works fine, but only slows down on wireless connection, then you will need to change the wireless network channel in the router settings. It should solve the problem. Most routers use the 6th channel, and if there are other routers nearby that use the same channel, the connection speed of your wireless network might slow down.
Based on the information you provided here, it seems that the cause of the problem is in the TWC modem. For that reason, I suggest resetting its settings to factory default. After the reset, the modem should work in routing mode, which means you will get Internet access when you connect a computer to its LAN port. If you need to configure it to work in bridge mode, you can do that afterwards.
Let me know the results after the factory reset.
I am following up with you to see if you require further assistance. Did the factory reset help solve the problem?