Changing a variable type inside of a Structure does not always reset it's value to the default value causing "Cannot parse value" error

Changing a variable type inside of a Structure does not always reset it's default value causing "Cannot parse value" error. Upon changing the default value or adding another, different variable type into the structure, this error will go away. If this is done with a another structure set as a type, then you'll need to set Editable on that variable to false.

Repro Rate: 4/4

Tested this in //UE4/Release-4.27 @ CL#18319896 and the issue did not occur there, it is a regression.

1. Create a new Blank BP project
2. In the Content Browser, create and open a new Structure (Right-Click, Blueprints > Structure)
3. Change the MemberVar_0 variable from Boolean to Byte

Results: Structure is not valid due to 'Cannot parse value. Property: MemberVar_4 String: "False"'
Expected: Structure is valid and good to go.