I saw earlier you mentioned it’s an Optiplex, so I’m assuming this is an onboard NIC.

I’ve never had an onboard NIC not work out-of-the-box in Linux. Wifi, sure, but usually just certain chipsets with proprietary/closed firmware. Dell usually uses Intel NICs and they’re usually pretty solid and well supported.

Check to make sure that the NIC is enabled in BIOS.

If you have/had Windows on this PC, did it work there?

Does the NIC show in lspci or ip a ?

Try an external USB NIC. Or an internal PCIe one if you’re comfortable with that.

This show was all that.

Not necessarily (platypus).

Biggest differentiator between the coconut and the hamster is the obvious lack of nipples.

Bizkit is right here.

So…if Steam is running in a Flatpak, and Borderlands is launched from Steam, how much can they even see…really?