No authorization for object creation, still getting object type creation popup

Hello Dear experts,

We are using SAP CRM7 and complaint management.

For some users, we have a requirement to have only "display" authorization to see the complaints, but no modification/creation on this object.

We used authorization object "CRM_ORD_LP" with activity = display only to complete this requirement.

But when going to the complaint workcenter and clicking on "New" with  , we do not have any standard message "You do no have authorization to create ..."

Instead, we are having the standard object type selection popup which appears empty. Please see screenshot bellow :

We tested and we have the same behaviour in standard : "WCF_IGNORE_ENHANCMT" parameter set to value A.

How come we do not have any "access denied" error message instead of this popup ?

Is there any customizing in authorization we could be missing ?

Thanks and regards,

Guillaume