This is a problem that has been reported for a few years now. It is typically referred to by the sellers as "ghost" listings. Yes, ebay is aware of it...yet it's intermittent, so really tough to pin down. If you can document as much as possible about when things were listed, when they sold, and when they came back, what categories they were in, whether any of your settings were changed in the new listing, what device you used to list them... etc., that would prob help them. They DO know it happens.
I had personally noticed that it seemed to occur most often when an item is bought near the time that it was about to relist again -- and what would then happen is their servers would be in the middle of relisting the item, and if some of the servers have it relisted, while some have it sold...the database syncing would be off. Even if not at the end of the cycle, it still feels like a sync problem. If so, even if they cannot fix it permanently, they should be able to run a sync process at a given time on the fields involved to keep it current so this doesn't happen. but, maybe it's a diff prob altogether.
