Water does not flow down blocks properly

This is not an graphics glitch. If you stand inside such a blinking water column the oxygen bar appears and disappears.

I've added a simple setup to reproduce the effect.

@maggstrom Like @Gulbaru said this is not a graphical glitch, this is a different bug.

I have noticed this with naturally generating water and lava in caves.

It only seems to effect the water/lava when it is going over the edge of a block. Water on a level surface flows properly.

Water falling straight down also works, but creates water source blocks under it.

This also works with lava...so it is now possible to create lava source blocks.

I encountered this happening on all sorts of mountain leaks (or whatever the heck you call them) in my amplified world.