Visual water level inside waterlogged blocks does not adjust correctly

Identical to MC-127270, so I'll just rip off the description from there:

 

When four stair blocks are arranged to create a "quarter-aligned anti-slab", and water is placed into all four of these, the water bulges upwards in the center instead of laying flat as one would expect. This effect goes away if the stairs are surrounded by solid blocks with the same Y coordinate.