Why does my minecraft server completely crash my internet?

So I run a server for my and my friends to play on. It worked fine until a couple of weeks ago (specifically after I factory reset my pc, dunno if that helps.) where it just starts completely crashing my internet.

It sort of fixes after restarting the modem and starting up the router again, but it consistently crashes after at least one hour of being up. Sometimes I can run it for 8 hours, but then it crashes. Sometimes I can run it for 2 hours, and it crashes. I don’t get any errors, and the only way I know it actually crashes is (if I’m playing Minecraft) all of my friends disconnect and I can’t speak on discord anymore. Otherwise, if I’m not playing, the internet would just stop working.

It’s gotten quite annoying and I really don’t know how to fix it, and I haven’t gotten any errors. My friend suggested Wireshark to see if I’m getting any IP logs, but nothing came up.