To reproduce, place some water or lava near some hacked water and make them collide in a way something should happen.
MC-126137
Waterlogged blocks don't help create new water source blocks or react with lava
Resolved
Fixed
1
Mostly fixed in 18w10c. Waterlogged blocks help create water source blocks and also react with lava in most situations except when the lava is above the waterlogged block. This is now MC-127079.