Check to see if you have anything blocking the path to the sink and dishwasher. Those overhead dish racks will block the path too so you might try rearranging things in the vicinity of the sink and dishwasher to see if that helps.
Hope this helps.
@CGrant56 Great tips. Ovearhead shelves etc disturb a lot in the game, seemingly not only sinks and dishwashers but also the laundry machines, tumble dryers and hampers, so don't put anything above them.
Could we ask the developers to please fix this so that it would be possible to decorate also above these machines without disturbing their function? If it's not doable, well that's fine as we know what to do to avoid problems with the machines.
For example, a couple of the sinks in the default houses in Mt. Komorebi don't work due to shelves above them. The sims simply can't wash up their plates. If you remove the shelves, they work fine.
