Is MS throttling downloads on Xbox One? MS Store app never updates / can't download...

THE PROBLEM:

BL: can't download new games or apps (otherwise console fully functional) -- I have 4 consoles and experienced the same problem at the same time (2 are Xbox One S and 2 are Xbox Ones)

My downloads/updates on xbox live seem to be throttled by MS and not my ISP or a lack of bandwidth.

Specifically, I have a fiber connection, and when I initiate a download, the speed starts out fast (~80mb/s) then within the first minute or so drops off to less than 1mb/s, then download speed is blank and the download ultimately times out.

Two apps were successfully downloaded: Netflix & Amazon Video. I stream just fine on the same device (Xbox One S)

THE SPECS:

I'm on a single-user, high-speed, network with 4 xbox consoles connected.

All devices have strong uninterrupted bandwidth.

All devices have been working fine for 4 months since moving to this location, to include many large game and app downloads.

I'm running a ASUS AC2400 4x4 Dual Band Gigabit Router; running thru ARRIS Surfboard SB6183 and all devices have high connectivity

Xbox One Settings Console Speed test (wifi) shows down speed ~70mb/s and up speed ~12mb/s

ISP is Xfinity

THE QUESTIONS:

Is MS throttling download speeds intentionally or unintentionally?

Is this the result of bottlenecking from too many concurrent users downloading from the same server (I imagine the initial spike in download speed makes a good case here?)

If so, is there a way to switch download servers mid download?

Are there additional settings in my xbox to take advantage of this lost bandwidth?

What Steps I've tried:

Power cycleSoft reset

Hard reset

Wire and unwired

Saving to Internal and external drives (each with 500+ GB space free)

On one console even tried the manual update via thumb drive with MS tech on the phone -- no luck, they said my console busted, yet it streams Netflix and Amazon just fine -- they are the only apps that downloaded after the hard reset

Where I'm left -- all 4 consoles work, but I can't download new games / apps.

Whenever I watch Netflix about 10 minutes in, on all 4 consoles this happens, the MS Store App tries and fails an update...and a message pops saying "update stopped" It seems like this New MS Store App is at the heart of all my troubles.

Anyhow, I've been suffering for 4 weeks now with no luck... If somebody has experienced this (I've seen other posts with this exact same issue, all closed, but never with a confirmed/definitive solution) please help. Thank you!

One of those similar posts was by mykreau titled "

Xbox Live downloads being throttled or bottlenecked?"

:)