CK II - Title become landless type title from savegame

[Aerotinge]

One line summary of your issue
Title become landless type title from savegame

Game Version
3.2.2

What expansions do you have installed?

Charlemagne,
Sons of Abraham,
The Old Gods,
Sword of Islam,
Holy Fury

Do you have mods enabled?
No

Please explain your issue is in as much detail as possible.
Take Mongol Empire (e_mongol_empire) for example.
The Mongols fires from event 60500, which set e_mongol_empire a landless title for an offmap invasion purpose.
An on_action event 60504 handle the aftermath, which set e_mongol_empire NOT a landless title just as like a normal title.
If I save the game at this point, quit and load from the savegame, e_mongol_empire become a landless type title.
I guess it is because the savefile did not store title state info and title state is load from "common/landed_titles/landed_titles.txt"

e_mongol_empire = {
    color = { 130 180 240 }
    color2 = { 255 20 20 }
   
    short_name = yes
   
    capital = 1457 # Kara-khorum
   
    landless = yes # this makes e_mongol_empire always landless if load from savegame?
   
    allow = {
        always = no
    }
   
    culture = mongol
    religion = tengri_pagan
}
...

Steps to reproduce the issue.
1.Start a game and type "event 60500", trigger The Mongols.
2.Wait till its successful invasion, now Mongol Empire title should be not landless title.
3.Save game and restart CK2, load the savegame.
4.Mongol Empire title is landless type title again.

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