Sims now more consistently wash hands in the sink closest to the toilet.
Fixed in Patch 1.99.264/1.78
please create a new thread if you're still experiencing this issue,
I am experiencing the same problem since the July patch. I've played several households rotationally since that patch in late July, and sims from every single household are not using the sink in the same bathroom as the toilet. It gets very annoying especially when I play in a big house. Sims wanders around from one floor to the other, some times it takes 2 whole hours to finish their bathroom business!
Apologies if someone else has posted this; I haven't read through the entire thread.
If I queue up another action for the sim after I tell them to use the toilet they will use the sink that is closest to the toilet and then move on to the next task. If I tell them to use the toilet and don't queue up another action they will use a different sink. This has been the case in the games I've played since the HSY update.
I don't know if that's helpful for anyone, or if there are exceptions to the behavior I'm seeing, but I figured I'd mention it.
