issues with the modem or the internet?

I started having random connection problems. My internet has gone down maybe 4-5 times this week alone. This is very rare normally. I have Spectrum and have never had issues, mostly. I pay for 100mbps internet because I’m a gamer, PS5, Xbox, PC, and switch. I have two smart TVs, Alexa’s, my iPhone, and a tablet, and my girlfriend will bring her stuff over occasionally too. I figure this is well enough as most of the stuff isn’t being used at once. I’m starting to think it’s my Netgear Nighthawk R6700v3. How do I tell if it’s faulty? It’s only a little over a year old but every time I try to check for firmware updates on the app it just says “there was a problem checking for firmware”. Does this affect my internet if I don’t update the firmware? It was supposed to be easy. I just have no idea if it’s a spectrum thing or my router.