Re-parenting BP that inherits & overrides parent-functions mark's Graph not editable

After creating a Blueprint class and then creating a function inside the BP, then creating another BP that inherits from the parent BP and overriding the original function inside the new Class and then after reparenting the new class causes the overridden function to be uneditable.

When clicked on, the graph is prompted with "Graph not editable"

1. Create a blueprint base class, eg. sub-class Character, name it "ClassA"
2. Define a function inside like "TeleportPlayer" with some basic logic
3. Create a new class "ClassB" inheriting from "ClassA"
4. Override the function "TelportPlayer" inside "ClassB"
5. Reparent "ClassB" to e.g. Pawn

Result:
The reparented "ClassB" keeps the overridden function "TeleportPlayer" as if it was declared in the class itself (intended), However, this function Graph is now marked as "Graph is not editable"

Expected:
The function "TeleportPlayer" inside "ClassB" is a fully functional & EDITABLE part of the new blueprint.