Strange LAN connect problem to hAP Lite

I'm fighting with getting a Lenovo M93P Tiny computer connected to my hAP and it's driving me crazy because the problem makes zero sense to me..

I have 3 other devices connected to the hAP (a couple of Pi's and a phone) and they're all perfectly happy (my hAP is set to allow for 13 host direct). But for some reason, this Lenovo will only receive a DHCP assignment with a specific cable and only then, when plugged into P3 of the hAP and only with that 1 cable). If I use any other cable I have to connect the Lenovo, DHCP assignment fails. Yet I can use any cable that fails with the Lenovo with any of my Pi's and it receives an assignment flawlessly. Same for my phone.

This very same Lenovo has no problems connecting to my home internet router, regardless of cable or port used and the WiFi is working fine as well (Wifi will connect to the hAP and internet router just fine).

So.. WTF?

Ken