I am using the infuser to make Protein and Dream Balls; I have not tested this with other infuser recipes yet.

Once a product is complete, it shows the progress of the next product being infused, but when the progress icon reaches completion, it restarts progress without adding the completed product to the output slot. So in order to infuse multiple items, I have to wait by the infuser and watch as each item is completed and remove it to make room for the next one. Once I remove the item, it stacks fine with the others in my inventory.

Confirming that this is the case as of 9.0.6, moving to internal. Thanks for the report!