I bought a new Xbox Series S but it only detect and connect to 2.4 ghz wifi , but not able...

Often this is a problem caused by the fact that the Xbox only has a 2.4 Ghz WiFi receiver built in, and 2.4 Ghz often connects at surprisingly low speeds due to interference in that band. For example, at my house my 2.4 Ghz WiFi bounces between 3 Mbps and
5 Mbps. The latter is fast enough to play HD, the former is not. So you would see buffering if that was happening to you.

To Samuel3201 point and your question about 2.4/5 GHz simultaneous. The xbox 360 will not be connected with 2.4/5 GHz simultaneously. Your router being 2.4/5 GHz simultaneous/dual band just means that it will be able to route traffic on both the 2.4 GHz
and 5 GHz clients at the same time, but not combine them. Think of it as the router having 2 phones and talking to 2 people at the same time as opposed to only have a single phone talking to one person, hanging up and calling another. Also xbox has only released
wireless adapters that are compatible on both 2.4 GHz and 5 GHz using the standards b/g (2.4 GHz) a(5 GHz) on the old wireless adapters and then the new wireless adapters can do those other standards plus n(2.4/5 GHz).

So this is EXACTLY the issue I'm having. Just bought a Cisco/Linksys E4200 for the sole purpose of using the 2.4 Ghz Wifi network for most of my home network needs and using the 5 Ghz network exclusively for streaming Media Center to the Xbox. Bought a new
black Wifi N dongle for my Xbox 360 Elite, but no luck. I can connect to the 2.4 Ghz network, but get network congestion issues and such-- It sees the 5 Ghz network, but won't connect. I've returned the xbox dongle and replaced it with another to no avail.
Any ideas? Sounds like a well known problem here-- but didn't ever see a resolution! If its just an issue with the E4200, I may have to return it and get something else. Recommendations? How do I fix this?

Hello Partha! I'm Kris and I'd be happy to help you with your question.

Before sending the console into service, I would suggest checking your router for a setting. There should be a setting for the 5Ghz channel where you can change the channel bandwidth. Increase it to 40Mhz or greater and that might fix it.

I have already checked everything you mentioned . My pc & mobile can detect and connection easily . Only the xbox is unable to find 5 ghz wifi.