I thought there was a setting in device manager for each network adapter for power management. Something about “allow this device to wake the computer.” You could try to uncheck that to see if that works, but there’s also another tab under properties I think for the Marvell controller which has something about allowing the device to wake the computer as well, but you have to scroll down to find it. I will try to post a picture of mine later today if you can’t find it. I don’t know if that will shut off the lights though.

Thanks for the suggestion, it's more about 'allowing the computer to sleep' than waking up. I have all that unchecked anyway.
There must be a way to tell the PC to stop power to specific USB ports when sleeping.

try this
https://www.asus.com/support/FAQ/1042220

Thanks for the suggestion, but I had seen that article before. None of that made any difference.
You wouldn't think that disabling power to specific USB ports when asleep would be so hard!