Xbox series x disconnects when the Internet is fine and other devices still stay connected

Im having the exact same issue with my Series X as DMcC1 though im using the modem/router provided by Spectrum Cable in western NY. Ethernet cable works fine on xbox one and any other device I connect it to, but when I connect it to the series X it will
connect for about 2 seconds and then disconnect and tell me i dont have an ethernet cable plugged in. It then alternates between connecting for about 2 seconds and then disconnecting for a while and then repeats the process. Wireless connection seems fine.
I guess im glad to know im not the only one.

Have the issue on my series x under WiFi , all my other devices are fine but when I use the series x under 2.4gh it’s really bad lag and 5gh is better but still laggy, only solution that I found right now is to use Ethernet and completely disconnect WiFi. Hope this helps!

I have the same problem and I've tried: reinstalling the game, rebooting my router and modem and Xbox, disconnecting my Xbox profile from battlenet and reconnecting it, giving my series X automatic Port distribution as well as doing it manually, I also removed a lot of devices connected to my router and checked the internet connection right after a disconnect but everything works fine

Ours has the same problem with Netflix and will disconnect from Live during a movie. I've tried all the trouble shooting suggestions and it still disconnects. Netflix works fine on all my other devices. No other devices drop the internet connect, only the
Xbox 360. I'm paying for this service, why doesn't it work???

This is happening to me aswell, there is another xbox in my house and it works perfectly fine and it doesnt happen on that xbox or any other devices, but on my xbox it will disconnect from the interent and when it does that it causes an issue with the interent
in the whole house which leads to every device connected to my internet to disconnect for about a minute