Totally accurate battle simulator unit creator

Human Fall Flat. The game is hilarious. Same with Totally Accurate Battle Simulator.

I have it downloaded internally and I am an Xbox insider but I don’t know what an Xbox insider build is

Thanks
Do you have the game installed in the internal storage or are you using an external drive to store the game?

If it's the second, can you try moving the game to the internal storage and disconnect all the external devices?

If it's the first, may I know if you are using an insider build / beta OS in the console?
If not, try this (can be a bit odd, but worth trying it)

go to Settings > Network > Advanced Settings

Once you’re inside the Advanced Settings menu, go to DNS settings and select Manual from the list of available options.
When you get to the next screen, enter 8.8.8.8 in the box associated with the Primary DNS and 8.8.4.4 in the Secondary DNS box.

Once the default DNS addresses have been changed, restart your console and see if the issue has been resolved at the next console startup.

(If that doesn't work use 1.1.1.1 as primary and 1.0.0.1 as secondary)

I’m on an Xbox one s and it’s not the first time trying to play the game, it used to work but then it just stopped working

Just to clarify, an insider build are buggy or not too stable OS versions (Depending on the ring that you joined)
To cover this possibility or if you maybe misunderstood my question. Check this article first:
https://support.xbox.com/en-US/help/account-pro....

If you indeed are using an insider build please leave the program, go back to an stable OS version and check the game