Call of Duty Black Ops 4 game share not working

EDIT: This has been going on for a few months, not related to days content issue of 8/6/2019

So I gameshare with my younger brother who owns BO4.

Before this I did not own the game at all, BUT I downloaded to 'Blackout beta' that lasted one weekend.

Once the beta was over, I liked the game so I began to gameshare with my little brother.

When the game fully downloaded and I went to start it popped up "Trail version has ended, click here to purchase full version' ect.

The console still believes I ONLY have the trial version. Ive tried making my xbox his home xbox multiple times, I've even tired a friends account and it still says the same thing.

HOWEVER, I'm sometimes able able to start the game by logging into my brothers account, getting to the start menu screen and logging out of his and into mine. I'm guessing it tricks the system temporarily because after a while I will get a pop up with "your
trail has ended" and it won't let me play again.

Things I have tried:

-Deleting the game

-Using other peoples account to set as home xbox

-Reset the whole xbox one, complete console reset

-Loading my account back onto xbox after reset, redownload game, and repeat will same result

Why don't I just buy the game from the marketplace after all this frustration?

Firstly I should be able to gameshare no problem.

Secondly I simply can't. When I go to buy the game from the marketplace it says "this game is already installed/you already own this game" and just gives me the option to press play.

So essentially its like the trail version is forever associated and linked to my account. This is the only game that does this and its very frustrating.

Any help is much appreciated, if there's a way to detach the trail version from my account that would be great. Thanks!

:)