Xbox One not working when Switching Accounts?

My brother and I want to play each other's games. I've switched his account to my home Xbox and he switched his xbox to my account. I was able to successfully download for example Dark Souls and play but when he logged in to play I got kicked out and was told an error message about logging into the account with the game or buying it.

I read in another forum and the Xbox support website that we could share and play at the same time, for example play online dark souls together. Or is that not a thing anymore? Did I miss a step? Anything else I need to do?

The kind of sharing you are referring to, requires your brothers HOME Xbox to be the one you are playing from and vice versa.

So if you have 2 Xboxes and 2 accounts:

Your brother's home console needs to be your Xbox, where you then log in with your account to play on.

Your home console needs to be on your brother's Xbox, where he is then logged in with his profile, still able to play your games.

This way is how I have been using it for the past 3 years without any issues. The important step is to make sure you set each other's Home Console on the other person's Xbox, to ensure he has access to the content, even though he is not logged in.

Hope this clears things up.