When I first tried the machine, I tried to load 5 (max available) but my sim would walk over and stand there for a moment, do nothing at all, then the interaction would disappear. I never had the opportunity to load anything. I tried this a few times and nothing came of it. When I tried to load the fruit/veg individually, the machine recognized the request. I was able to load the harvestable and then activate the fizzing. After that initial success, I again tried to load 5 and it finally worked.
The npcs who try to use the machine at the community lot also don't seem to have any interactions. They walk up to it and nothing happens.
