ASAs "ReserveAddress"

If you create an asset with deployer account that it is different to the reserve account the “non-minted” tokens go to deployer (creator) and not to the reserve. Why does it happen?

more context:

{
from: deployerAccount
assetManager: managerAccount,
assetReserve:managerAccount,
...
type: TransactionType.ACFG,
}