CK II - The conditions "would_be_heir_under_law" not work when modding

[Adwa]

One line summary of your issue
The conditions "would_be_heir_under_law" not work when modding

Game Version
3.0, but being modded

What expansions do you have installed?
All of the above

Do you have mods enabled?
No

Please explain your issue is in as much detail as possible.
The conditions "would_be_heir_under_law" won't always lock on my first son
When I am elective monarchy, once my first son be elected to heir, he will not be the heir under primogeniture anymore

Please check more detail with code and image at
https://forum.paradoxplaza.com/foru...eir_under_law-not-work.1128603/#post-24853444

Steps to reproduce the issue.
Couldn't reproduce the issue.

Upload Attachment

 

[Adwa]

Do anyone know what's going on?
Or let me post the example

Here is the code

elector_vote_strength = {
    days = 1
    additive_modifier = { #The heir of primogeniture
        value = 10
        FROMFROM = {
            would_be_heir_under_law = { who = FROM law = primogeniture }
        }
    }
}

elector_selection = {
    days = -5         #If below 0, ROOT is not valid to be an Elector.
    additive_modifier = { #The heir of primogeniture
        value = 1000
        FROMFROM = {
            would_be_heir_under_law = { who = FROM law = primogeniture }
                                 #Both "who = FROM" and "who = ROOT" is same here
        }
    }
}

Please focus on "would_be_heir_under_law", in this case, I expect it will always target on the heir of primogeniture

For example, Kindom of England lead by William

When Robert is not the heir, everything alright, he is seen as the heir under primogeniture

But when Robert become the heir of elective, he immediately lose the position, he's not heir of primogeniture anymore