Playground Select Car Pack purchase for second time weird problem

Hi to everyone this is my first post!

If you remember the Playground Select Car Pack was free between August 4 and August 11 is via the Forza Hub app.

So download it from there. Now the xbox store has on discount the Storm Island Expansion and the Playground Select Car Pack and I bought the storm island. Not remember if i had the Playground Select Car Pack so i checked on store and i saw that i can buy it so i assumed that i don’t own it! So i bought it for 1.25€ and when i went into the game realized that i already own it, first i saw it in the dlc list at the xbox my games and apps and second when i played the game and i saw that i have 2015 Volvo S60 Polestar to my garage already.

Why this happened? Can any of you who downloaded the Playground Select Car Pack from forza hub can confirm that he can buy it from the store again?