Usually they are not self assign, but these were. They were all in my inbox, not applications. I made sure to not do a shop before the 18 days. The ones that disappeared were ones I had not done in months. I had some shops in my inbox that yesterday appeared in applications ( someone took them from my inbox and put them there, not me) And now they're disappearing from applications. The shops I still have have date changes.
If the initial date window of the shops was the problem, they should have changed the dates, sent an email stating the change, and give us the option of cancelling shops if they no longer work with the new dates. But, it is not cool to just remove shops with zero communication from them.