In the player house, you can put a lot of items in chests quickly by using the ‘deposit ingredients’ button. When using this button, sometimes items will not move in to the chest. This seems to happen when there is one of a particular ingredient already in the chest. If there is more than one of that ingredient in the chest then any in your inventory will move correctly.
For example, if you have one Rotospore in the cauldron chest and one in your inventory, clicking ‘desposit ingredients’ will not move it in to the chest, even though it should. If you move the Rotospore from your inventory in to the chest manually, so there are two in the chest, any subsequent times you have Rotospores they will move correctly when ‘desposit ingredients’ is clicked.
This isn’t specific to Rotospores. I’ve seen it happen with lots of different items in this scenario.
I should add that this bug only becomes apparent when there are no free slots in a chest. If there are free slots, in the example above it would move it in to the chest but use up a free slot rather than stack it with the existing one.