Fortune 3 Pickaxes don't work,Everytime i mine diamonds or coal or any other ore that drops the item itself... It keeps on giving me ONE! And its not just my bad luck.

Why wont my Fortune 3 Pickaxe work? Everytime i mine with my fortune 3 Netherite Pickaxe it doesn't give multiple of these so called items, For example i mine diamonds and i only get ONE.
Trust me it's not bad luck its just broken. i should be atleast getting two diamonds from mining a single ore,if my minecart despawning isn't already a bad problem. This has already ruined my day.