I've heard that listing the player character as an "entity" is generally bad and confuses the AI a tad, information about the player is best kept in the System Prompt Addition.
Maybe changing "Partner: None" to just "Unmarried" could help, or just rewording it in some-way to be more strict that the player isn't married.
I also like to use the dictionary to properly start scenarios, just make a dictionary entry for START GAME and write "the player is unmarried, the player starts in their home, blah blah" and since it never comes up again, those prompts aren't locked in the AI's focus, and won't influence it's behavior outside of turn one.