thesugarat,
first of all, thanks for your reply!
So here is what's going on:
(1) if I connect the Pineapple Mark IV to a PC with the ethernet cable hooked to the PoE LAN port, I'm able to access the Pineapple's web-based control center (PCC) from the same PC and from an another device (i.e Mac). Everything works flawlessly!
Now,
(2) if I connect the Pineapple to a Mac, I'm not able access the PCC. Not from the Mac, neither from an another device (PC).
Any clues?