Can’t get LAN System Link working with multiple XBOX consoles

Hi

I’m hoping someone has some suggestions on how to help with this. I’m trying to sort out a few different XBOX consoles with System Link.

First I tried an Original XBOX and a Series S with Star Wars Battlefront 2, and tried a direct Ethernet connection between the two. That would recognise any party with the system link no matter who started it.

I then tried an XBOX 360 and the Series S with a connected Ethernet with the same game, and still no joy.

I then tried Gears of War 3 with an XBOX 360 and Series S, with the same Ethernet cable, and a different one (to make sure it wasn’t the cable) and that wouldn’t find each other.

Next I tried Gears 3 with an Ethernet to the router from the Series S, an Ethernet to the router with the XBOX 360 and a wireless connection with an XBOX One, they were all connected to the network, but again still not finding any party no matter which console started it. I made sure that the DLC was on all 3 consoles too.

Finally I just had the Series S and XBOX One connected via WiFi but they both couldn’t find the party host.

Does anyone have any suggestions? Star Wars Battlefront 2 is supposed to be compatible with all 4 consoles on System Link. I did read Gears 3 was a bit dodgy, so will try Gears 2.

Thanks.