Sims shown as alive in family tree after death

Product: The Sims 4
Platform: EA APP-PC
Which language are you playing the game in? English
How often does the bug occur? Every time
What is your current game version number? 1.126.73.1030 DX11
Steps: How can we find the bug ourselves? Sims set as ghost occult in CAS, then use their own gravestone from inventory to "return to netherworld" in game. (no specific death cause or occult [tried on merfolks and vampires]...)
What happens when the bug occurs? Image on family tree is grayed-out at first when sims passed away, but after reloading game their image is colored again and no cause of death marked. However sims is no where to be found. 
What do you expect to see? I expect my ghost sims to stay dead and not be regular sims suddenly
Have you installed any customization with the game, e.g. Custom Content or Mods? Yes. Used mod to try to "teleport" that dead sims to world, does not appear. Should be really gone...
Did this issue appear after a specific patch or change you made to your system? IDK, never played like this...