: Two Xbox Ones with Xbox Live over an Apple Airport Extreme network?

: Two Xbox Ones with Xbox Live over an Apple Airport Extreme network?
So I have two Xbox Ones on my network, with wired connections back to my 5th gen Airport Extreme (Time Capsule). I had run one Xbox One for a year with no detectable trouble, but after adding the second Xbox
One, we noticed problems with running online Xbox Live connections at the same time including slow speeds, inability to connect to game servers, dropping off, voice chat failures, and even complete network crashing.

Since then, I've discovered that Apple routers don't play well even with one Xbox, and I was apparently lucky to have had good connection for as long as I did without configuring the Airport and the Xbox, due
to the Xbox's preference for unPnp (unsupported by Apple) and NAT forwarding, etc etc. I've read a lot of confusing and contradictory info about how to optimize the settings for running a single Xbox on an Apple Airport Extreme network, usually through either
putting the Xbox in a DMZ or through port forwarding, and I'm honestly not sure what configuration is best.

More importantly, I'm not sure what (is any?) is the best way to configure for TWO Xboxes to run Xbox Live connections simultaneously. Is it possible? If so... how? (Should I even mention I *also* have an old,
seldom-turned-on Xbox 360 as well? No? probably not...)

If it matters, it's a cable (Midco) 150 Mbps connection to an Arris Surfboard SB6190 modem to the Time Capsule (A1470) to a Netgear S350 Gigabit switch out to the Xboxes via Cat 6 cables.

:)