Can't put urn in sims inventory anymore

I had a sim, named Arielle, die from laughter while I was present. It very unexpected and sad. I have the Mortem (by Sim Realist) mod installed, have for a year or so. I did a funeral for Arielle and got the Urn after. I was able to put it in her father's inventory. The family brought it home and I placed the urn in her room. I engraved the epitaph before placing it. Her parents autonomously take turns mourning there every day.

I had originally planed to move Arielle and her sister Andromeda out together after Winterfest, but Arielle sadly died on in the last hours of Winterfest. They were going to be roommates since they are very close. I figured they could still be roommates if Andromeda moves out with the urn and later adds the ghost of Arielle to the household (I can't add her now since the household is full). However I discovered today that I no longer have the option to put the urn in anyone's inventory.

Is this by design? I generally place tombstones in a shared graveyard rather than keep urns in the house. This is my first time trying to move an urn when it's not the day of the funeral so I'm not sure if this is a game thing, a mod thing or what. I can try to move Andromeda out, then see if I can add Arielle to the household, then move her out to live with Andromeda. At least then she would meet her youngest sibling (whom was born after her death, it's been wild).

Is there a workaround for adding a ghost to the household?

Note: I also have Scumbumbo's packing creates mod (updated by Basemental on Sep 10th 2021). I'm using this for moving Andromeda out with her things plus some of Arielle's things. This is the most recent mod I've added.