I have 3 Objects, 3 Users with Standard Platform User profile and 3 Permission set for each User. In the Standard Platform User profile, i haven't given any Create, Read, Edit, Delete, View all, Modify all permissions to any of the 3 objects.

Object1 is master to both Object2 and Object3 with MD relationship.

User1 have Permission set1 with Read access to Object1, Object2 and No access to Object3.

User2 have Permission set2 with Read, Create, Edit permission to Object1, Object2 and Read permission to Object3.

User3 have Permission set3 with Read, Create, Edit permission to Object1 and Read permission to Object2 and Read, Create, Edit permission to Object3.

Now User2 able to create Record in Object1 as he have Create permission in permission set2. Even though User3 have Create permission in Permission Set3 for Object1, he is not able to create record in Object1(New button is enabled as well).

What might be causing this issue?