New router isd and old isd - Time Warner Internet

This question is about "New router isd and old isd", with Time Warner Cable internet and apps. just baught a new netgear router and hooked it up to my modem after two hours back and forth between twc and netgear its finally working. the only problem is now i have my old ssid and the new netgear one. both work and when i try to login into my modem from twc it does not let me. should i be worried? is this bad and does it confuse the router?

This topic covered New router isd and old isd, and TWC cable internet service.