Xbox S wifi connection makes modem flicker wifi signal to Xbox and other devices.

What specifically would allow the Xbox 360 Wireless Networking Adapter to connect while the built-in wifi would not?

My Xbox 360 S detects a wireless signal with 4 bars, and I am testing it while sitting it right next to the modem, so there is no issue with signal strength.

My Xbox 360 S's built-in wifi is able to connect to a hotspot, and it is even able to connect to my neighbor's wifi from my house.

1. Is your xbox the only device on internet ? (try to shut the other down and look if it helps)

2. Wifi or lan ? (by wifi connect with lan to your modem)

Hi Excel. My name is Kyle and I'm an independent advisor.

What happens when you try to connect to your WiFi? Do you get any errors?

If your Series S connects to other WiFi networks, there may be an issue with your router or internet connection. Have you tried any troubleshooting steps so far such as restarting your router/modem?

You may need to configure your router to improve the WiFi signal and make sure your Xbox's connection isn't being blocked by the router's firewall. WiFi signal may be improved by relocating the router and changing the WiFi channels in the router settings.

Additionally, make sure the ports for Xbox Network are open in your router settings: https://support.xbox.com/help/hardware-network/connect-network/network-ports-used-xbox-live

For help with troubleshooting your router and accessing router settings, please contact your internet provider or router manufacturer.

Thanks,
Kyle

check that nothing is physically interfering with the wifi signal like other devices, it would be good if you will check if these problems also occur connected by ethernet, so you would know if it is wifi or xbox problem

i did that and it can't connect with my wifi anymore.

i already reseted my modem twice and resetted my xbox twice.

on my other devices my wifi works fine