Hey there.
Sorry that you found this. Look like it was a problem with a DQ11 mode fix I implemented a few updates back, namely the one where recipes that contained the same ingredient item multiple times were only removing that ingredient once from the inventory. Looks like I goofed and somehow made it so that removing independent items from the player inventory no longer worked correctly.
That has been fixed in the new update, which has already been uploaded.
Thanks,
-Ramza