Hi,
Associating an object to a transaction in SU22 or SU24 does not ensure that the object will be checked during transaction execution. SU24 is mainly for help in maintaining roles.
You need to either activate the associated checks by configuring the same in IMG customization (if applicable) or by modify the transaction by inserting the correct ABAP statements in the corresponding ABAP code. Only then can the object check be active.
You may need to have a discussion with the functional team contact and the developer to investigate a proper solution.
Regards.