Flowers369 wrote:
The herbs on the table sometimes, but not always I think, disappear as well. Also, I have occasionally made a potion and nothing happens. The pot just sits there empty, no explosion, no potion ready, nothing. I have to collect 3 more herbs and try again. When this happens, I have collected 3 more herbs, the villager uses 2, leaves the third on the table, and the potion is made or explodes.

I've had the same problem. It seems to happen when there is still some potion in the pot and it has to be emptied.

A way around this glitch is to use one person to empty the pot and another to make the new potion.