Can't /testforblock Lava source and Lava changes when Placed

When you go /testforblock ~ ~ ~ minecraft:lava it doesn't work, it says that there is lava there and that it expected lava, so its a bug. And when you go /setblock ~ ~ ~ minecraft:lava it places it, but if you do it again it still places it, but if you do this with a normal block, the second time you do the command it should say Cant Place Block. Lava Acts really wierd, and it doesn't work. A note is that I am doing this next to lava blocks, so I run the command in lava that is in a 3x3 Grid. Maybe this doesn't work when next to more lava, IDK i haven't tested it, but It certainly didn't work for me... And when I do a /testforblocks and build the same type of lava in the right configuration and everything it doesn't work. When I remove the lava and do /testforblocks it works. So something wrong with the lava...