There is no "power management" setting under the Advanced tab. There is a "Transmit Power" setting; that's at "5. Highest".
Are you recommending the BIOS and wireless driver updates because they have fixes for this problem, or because you just suggest those any time you don't have a clue? Installing BIOS and driver updates willy-nilly can easily introduce new problems, and I'm not going to do it if there's no indication whatsoever it will help with the existing problem.
I'll be delighted to hear of any substantive information you can provide. If you don't have any, please advise on how I can escalate to a party that may have information on this problem. Thanks for your time.