It seems I was mistaken. I couldn't reproduce the result. I went to the new save, which was working, and attempted to have my sim go home and come back to see if it would work, and it wouldn't. No longer is there a star or option to greet. In my other save files that I loaded I still can't get it to work, and I've tried multiple vet clinics in the gallery. If I have done this without mods, on a fresh new start and it isn't working, then it isn't a cc or mod.
It worked on a new gallery clinic only once, but once my sim left the lot it went back to broken. I've tried placing other clinics, but it seems even if it were to work (already a slim chance of that since it only worked once) the second my sims goes home it no longer works.
At my wit's end. ☹️