Ingredients Collection Stuck at 14/16

I am working on completing every collection and I've almost finished. However, there is a bug where I have 14/16 ingredients collected. The collections page shows the pictures for the two missing ingredients (Knotweed and Shrivelfig) but no check mark. I have re-tried every method of acquiring them but the collection doesn't update.

Has anyone else had this bug or found a fix? I can't find anyone online with a similar problem. Thanks for your help.