To enforce sending BitLocker key to AD, you need to:
1.Get ID and password from the needed computer:
manage-bde -protectors -get c:

2.Make a backup to AD for selected ID
manage-bde -protectors -adbackup c: -id {enter id of Numerical Password ID here}

If you see below error
this means that AD is not correctly set - computer has no permission to save backup to AD.