I had a prospective buyer reach out yesterday to say they couldn't choose colors for one of my items as it kept coming up as sold out. I went and looked at the listing in question, the quantity was marked as zero. I have no idea why a sold out item would be in my active folder, normally it automatically goes into my sold out folder and then I renew, if feasible.
Just thought I'd pass the information along, luckily the buyer reached out and I fixed the listing but who knows how long it's been like this and how many other prospective buyers just wound up leaving my shop : (