Cannot connect to Xbox Live on my Xbox One while playing an Xbox 360 game

The games are all digitally owned in my library. There are no discs. I had no troubles with this on my original Xbox One that recently broke and required me to buy a new Xbox One S. The emulator I am referring to is the internal emulator that all Xbox
Ones run when playing a 360 Backwards Compatible game. When I install a 360 game and try to run it on my Xbox One S, the game will load HOWEVER I cannot connect to Xbox Live while in the 360 emulator. Due to a recent troubleshooting that suggests uninstalling
the game and clearing 360 cache and profiles, I would need to redownload my xbox live profile for the 360 emulator ON the One S. Since the emulator WON'T connect to Xbox Live, despite my Xbox One S BEING connected to Xbox Live, I cannot download my profile
and therefore cannot play and save my progress. I've tried with multiple games but they all give me the same issue of being "unable to connect to xbox live". I've tried all of the Mass Effect games, the Dragon Age games, Star Wars: The Force Unleashed games,
Banjo-Kazooie, and Fable series of games and NONE of these will allow me to connect to xbox live.

Wont work because you changed your gamer tag and have not redownloaded your profile on the 360 emulator.

Quick simple fix as long as you know your email and password for your account. Just follow these steps.

1. Launch ANY 360 backwards compatible game.

2. Once launched hit the start and select button at the same time (small little buttons on either side of big xbox button on controller) 360 guide box should come up.

3. Click on download profile it will ask for your email and password for your account and then you should be good to go may have to choose to sign out first but it should have already signed you out when you launched the game.

My password is less than 16 characters. My account isn’t on the emulator anymore because one of the steps on the other page told me to try deleting my account off the Xbox and re-downloading it as well as clearing the cache for 360 games. The thing is
that since I cannot connect to Xbox live I can’t get the account back on there at all so there are very few games that I can even play without signing into an account on the 360 emulator. And just to reiterate I can still play Xbox one games online fine.
However this issue with 360 games and the emulator and not connecting to Xbox live has been going on for at least six months for me.

Factory reset is done, now I cannot sign in to Xbox Live from the 360 emulator. I am online with the Xbox 1, playing multiplayer and watching netflix, connection test shows that everything is working.

When I open 360 games, my gamertag pops up as signed in, but not connected to Live.

QUESTION:

My brother and I currently have separate Xbox Live accounts connected to a local Xbox 360 console. If we decide to transition our Xbox Live accounts to the Xbox One, will only one of our accounts be allowed to play games that we purchase or will we both
be able to play games as long as they are on the same console? I cannot afford to buy two copies of the same game just to play on our unique accounts on the same console.