In theory flapping between 10 and 100 should be less probabile than flapping between 100 and 1000, because both 10 and 100 need the same 4 wires, while 1000 needs all 8.
But sometimes It Is something else, only a few days ago:
Hap ax S ether 2 to 5 not working with some device - #2 by jaclaz
Though It seems that the issue Is with the PC network card (or on its drivers, or however the OS) It Is also possible that there Is some kind of false contact (physical incompatibility) between the RJ45 plug and socket of the network card, while the same plug makes contact on the hAP Lite socket.