Can't Access VIP Membership and Cars aren't free in my garage

Hello im going to make this short as possible Xbox Support sent me here. All our downloaded content is purchased on our grandfathers account so it doesn’t get mix matched we buy all games and DLC there. I am trying to access the VIP membership and Car pass to its full potential but I cant i tried everything. I cold rebooted the xbox, and reinstalled forza along with the DLC. The content shows up in my game buts its not free to buy I have to spend in game credits. While on his account the cars are free as promised before buying the pack. Before you ask yes the account where all downloaded content its selected as home xbox. Any help is appreciated.

Same with me did you find a solution.

The cars will be in the game for everyone who has a profile on that Xbox.

The cars will be free in the game only to the account that made the DLC purchase.

Therefore, if your Grandfather’s account purchased the car packs, your grandfather will get all those cars for free. Everyone else will get access to them in game but they will have to spend their in game credits to use them.