I was spilling buckets of water for sugar cane while playing in my realm on the xbox one version 1.2.1 and about every other attempt to spill the water it would make the sound as if it were, but the water wouldn't come out. Sort of like some of the time in realms when you place a block and for like 1/10 of a second you can see it before it dissapears and you have to lay it again.

Steps to reproduce:

1. dig trench for water one block wide, 1 block deep, and several blocks long.
2. start at first block of trench, lay a block of water, and again skipping two blocks each time.