I was in a underground base that I am working on and it started raining on the surface, the rain then started coming through the ceiling as if there were no blocks in the way. I don't really know how to reproduce it.
Environment
Windows 10 pro latest java as of 4/22/20
I received the same issue. I step towards it and the rain disappears but when I move towards it it starts to rain again. YOu can stop it by placing a block over it.