I encountered this issue yesterday while planning wedding outfits for my Sims.
I had planned an outfit for both the groom (a Sim in my household) and the bride (a Sim outside my household). However, only the groom appeared in the correct outfit during the wedding.
When I opened the wedding planning panel, the groom’s outfit showed up correctly, but the bride's outfit was incorrect in the preview image. Strangely, when I entered CAS to edit the bride, her outfit was actually correct.
During the wedding ceremony, after the Sims moved in together, the bride suddenly switched to the correct planned outfit without any outfit change animation—it just appeared magically after she joined my household.
I also attempted to change the bride's outfit using testingcheats, but the planned formal outfit wasn’t available. However, when I entered CAS, the correct outfit was there again.
Here’s what happened during the wedding:
Before the bride moved into my household: She wore the wrong outfit.
After the bride moved into my household: She instantly switched to the correct outfit without any animation.
EDIT: I think my case is related to this bug: [OPEN] [LS] Sim from Cupid's Corner Gallery won't change after CAS edit - Answer HQ
The bride if from cupid corner's gallery.
