ArmedDillo

This is happening in 1.16.4 If you hold a stack of at least two bowls filled with liquid, and ctrl-right click to transfer small amounts of it into a different container (barrel, bucket, potentially another bowl?), the minimum amount is added to the target (0.1L), no amount of liquid is removed from the bowls, and the bowls remain in the same stack. This allows you to get an infinite amount of any liquid you already have at least 2L of. From fooling around with it for a few minutes, it seems like buckets behave the same way as well; ctrl-right clicking a container with a stack of buckets adds the minimum amount a bucket can transfer (1L) while not removing any liquid from the bucket stack. Also, picking up a part-filled bucket while you have a full bucket in your inventory, seems to create a stack of two full buckets (and not two separate buckets with different amounts of liquid).