Xbox series s unplayable due to lagging

The other Xbox’s was checked it the same position.

What could it be in the hardware that’s letting it connect to the Wi-Fi but not playing properly when I go to try and play a match

I don’t think so.
Depending on a lot of factors, the Wi-Fi connection can’t be reliable.

However, you can try placing your Series S where one of the other Xbox are located (in case your Series S is in a different room). But if you think it can be a hardware issue, you can return the console to the seller.

If that worked would that prove that the Wi-Fi receiver in the Xbox is at fault ?

As my Xbox series x and Xbox one connect and play perfectly online via the same Wi-Fi

I'm afraid to say, but it is not possible to diagnose your console, and we can only speculate about the real issue. So I can't tell you if it's really something in the hardware that's causing you some trouble via Wi-Fi

However, you may find helpful to change your DNS in case you still didn't try to connect your console via Ethernet:

Open settings on your console > select network settings > advanced configuration > DNS settings > select manual.
Insert this IP address 1. 1. 1. 1 and then this other one 1. 0. 0. 1.

Restart your console before trying again.

Note: You may want to try with 8.8.8.8 and 8.8.4.4 as well.

Thank you,

Arturo.

Before considering the Xbox as a faulty device, would be great if you try to connect it to your router via Ethernet and not Wi-Fi connection.