Entity NBT Blocks are Broken

In all of my mods where I try to use the "Get logic/number/text NBT tag" or "Set logic/number/text NBT tag" blocks, they never work, and they just default to false/0/nothing.

I would try to use the vanilla "/data get" command instead, but you can't receive the output from a "Run command" block, so I'm stuck.

I would like to know if I am doing something wrong, or if MCreator itself is broken.