[MC-122895] Lava will fall as fast as water when placed in a certain order

Lava will fall as fast as water when placed in a certain order (see attached video).

I'm guessing it has to do with the water overwriting the lava's fall speed for some reason.
This bug happens on both singleplayer and multiplayer.

Attachments

Confirmed. Note: In the future, please test bugs in vanilla Minecraft – optifine and other mods can cause behavior differences.

I did test it in 1.0 without optifine, and on a 1.12 server, but I will try to keep that in mind for the future.