Secret Lover glitch with death notification

Royalty & Legacy: My Sim has a secret lover and it was fine but then I got a notification of a sims death and suddenly a pop up appears saying they are now the partner of my sim.

I reloaded my save, the same happened. I loaded it again, same issue. I ended the relationship, started over, happened again when another death notification popped up.

Death of a non household sim is the trigger. Secret Lover is not in the played household.