Xbox One X won't recognize my lan cable. Any suggestions?

If the cable you know is good (it works on other devices) then there is a high probability the LAN port on your xbox is the issue. To repair that would require logging a hardware support case.

If the cable is a cat6 cable it should work. If not this could be the issue. If one of the cables you tried is a cat6 then it should be an issue with the console. In that case i would recommend to go to the device support page and set it up for an repair
or talk to the store where you bought it.

Hope that helps.

Maybe you need to find a new Ian cable

Hi HAD0UKEN,

Thanks for reaching out to us here on the Forums!

We understand that the cables are not working on the console itself but it does on other devices. Have you been using the same brand of cables each time?

Considering everything, it would seem that there might be an issue with the port itself on the console. I would recommend looking into getting the console repaired.

Check out the following link
Getting
your Xbox console or Kinect sensor serviced for more information.

Please let us know if you have any other questions, concerns or input regarding this situation

Trying another cable is the easiest option but also make sure you have it plugged in all the way. Most of them click into place. I have had people yank them out improperly breaking the small tab and then it no longer clips and locks into place making
it loose an ineffective.