I realized that every time I go to the add/remove materials section for my vocab list, and select to add terms individually, there are almost 100 words being removed from my study schedule under "Removed from list".
I noticed this as there were some common words not showing up in my schedule like 風/かぜ. It turned out this among others was in this long list of terms being removed every time I updated my vocabulary materials. Every time I go in to add/remove materials, this list fully populates again with "Removed from list" terms i.e. I can't update my materials and click save without having to go in and add all these terms one by one again.
I assumed this might be part of the duplicate/standard reading wipe recently, but given basic terms like 風/かぜ I wondered if this was the case.
So sorry for the delay! Do you mind letting me know the name of the schedule with this issue, and a screenshot of the top of the list?
Also, just to clarify: so your schedule *Should* have 風 (for example) in it, and it indeed comes in up in studies. However, if you go into add/remove, it'll appear in "removed", and if you save on that page, it gets removed?