So I tested the new water. It looks like it is faster? Feels like it is.
But then it failed, no errors shown though.
The image describes what I did.
I did some random holes.
Then I dug both green channels in the picture.
After they complete it, I started digging the orange channel.
When they mined the first block from that mine region, marked in the red circle, the water popped up (?) and flooded the sand area for some reason. It can be seen that the water spread in a circle area with its center at that first block mined.
Hope it is useful for your quest on fixing the water @Albert