Resolution: Works As Intended
Affects Version/s: Minecraft 18w16a
Fix Version/s: None
*This issue in MC started from 18w10d.
So when lava or water is going to a flowing state, the observer normally detect the change and give a redstone pulse.
This behavior was very VERY useful for Compact Stone Generator and Tick-speed redstone delay circuit.
Now, because of the recent change with the water/lava update, the observer doesn't detect the updates from those.
Here is a quick view of what is happening now:
*Accidentally left my micro off, no voice sound.
I would really like to see this issue get fixed. Because if a release of 1.13 come out and this is not fixed, many and many many redstone build would be broken.
(By the way, this issue is NOW very related (not duplicate) of the bug report MC-107664)