Duplication of water source when leading mob onto fence

When leading a mob onto a fence whilst holding a water bucket (in survival mode), a non flowing water source block will appear whilst not depleting your water bucket, which still functions regularly. This waterlogs the fence. It acts like a ghost block, as it does not put you out when on fire, and when the fence is broken the water disappears. However, when walking through it, it still has the viscosity of water, slowing player movement. Works on all types of fences, and when leading all mobs.