I'm in Seed: 4357639008311401092
I came from underneath to see this issue. You can see from the screenshot there is no reason the water above from what seems to be the ocean should not be flooding this cave. It is suspended w/o any trap doors etc. etc.
[media]
I broke the one of the blocks and the water flowed as expected
[media]
Environment
I'm in latest release 1.14.2 vanilla on single player
Java 1.8.0_51 64bit
Windows 10: Intel i7 4790
Nvidia GTX 1070
Duplicate of MC-32813.