Sims can't reach "soulmate" status

This is my first time posting something here, I hope I'm doing this right :) I just had to say something because it was really bothering me lol.

My two married sims both have the soulmate aspiration, I need them to become soulmates to progress with the aspiration and complete it. They both have maximum friendship and romance bars but I cannot get them to become soulmates. Their relationship profiles say "lovers".

I have custom content for CAS and build mode, but nothing crazy. No gameplay mods either.
I completely removed all my CC at one point, the issue didn't go away.