: Any idea why games installs or any downloads at all are only a fraction of my 1GB...

It's simple your gigabit speed isnt gigabytes per second

Its 1gig /8=128MB

When you get a speed rating it's megabit

Or in your case

On top of that you have to consider distance and the amount of nodes to the Xbox servers

Which can be hundreds and not all will be gigabit speed

the disk only installs part of the game, not the full game.

pretty sure it doesn't install any of the xbox updates that MS puts on the disks, which is like 1gb of space wasted. all my games spin at start up but by the time im at the title screen it stops.

Yes it does work fine with all other devices. I have around 1GB of download speed using Ethernet with my other devices but this happens only with my Xbox.

And yes, it is the same with Wi-Fi as well even worse! )

The NAT is open but the download speed lowers to 90mbps when I shutdown the Xbox after having 900mbps of download speed

Any idea how can I maintain it ?

I have tried uninstalling the program, but it only shows 1GB uninstalled while the program occupies 130+GB, so I am not sure about what is going on there.

The 1GB program is just the launcher (or the installer if you're installing the game from a fresh download.). When you install for the first time, the data files - essentially 'the game' - can be installed into a different folder or drive to the 1GB initial download.

As for why it's not working, I'm afraid I can't help you with that currently. There are videos on YouTube with guides on how to manage the installation of MSFS 2020 that could help you with the reinstallation, potentially without needed to download the whole 130GB again if these files still exist on your system.

The game is designed to be modifiable and the main install folder won't be locked.

Any idea as to why it won't install at all?