So, a couple months later here is an update. While on the phone with tech support for a few hours, I kept trying to move items around while they were "looking in to the issue" and asking me to try again, and eventually, apparently for no reason at all, it just started working again. The QB person was of course happy, but could not provide me a reason for it not working in the first place, in case I encounter this issue in the future I wanted to know. So it worked for about a month and now I am faced with the same issue again, frequently if someone else/other user adds the items, but also occasionally if I add the items. They keep providing the same copy and paste solutions when others ask for help on this topic, I wonder if anyone else is still having this issue and what has solved it for them.