Maybe a switch where some ports are PoE and some are unpowered
I have a TP Link Ether over AC adapter going into a TP Link fast switch with SFP ports. From the switch I use a TP Link media converter via fiber optic to a media converter next to my Aurender. From there into the Aurender. Dead quiet.
I had a similar Ether over AC adapter by Netgear and determined that was the cause of my noise. Got the TP Link version that was 2 x as fast and it's super quiet.