Cannot overwrite variables from parent class

So, the objective here is to make a weapons system. I start with the parent class: an abstract weapon blueprint which defines what things are going to have all weapons (model, collision, animation, maxAmmo…).
Then right-click on the abstractWeaponBP > Create new child class. I name it “shotgun”. Then I edit things from that class using the editor (I set the model to one of a shotgun, I adjust the collision box to the model…) but time is up and I have to go, so I save everything and close the engine.

The next day, when I come back I cannot edit a single thing inside “shotgun”, the tag “isDataOnly” is now true and opening the blueprint shows an empty window Why? and how do I get things done now? Because I need to be able to edit the position of the model, size of the collision box… and I cannot do that using setters with the precision I have using 3D gizmos.

There is a blue hypertext “Open Full Blueprint Editor”

Yep, in the ClassDefaults window, there’s a hypertext that allows doing what I needed. Thanks a lot!