Block with gravity breaks upon landing on another one of those blocks

If I set a block to have gravity (or make it spawn as a falling block) it cannot land on another one of that same block without breaking.

There is no unique bounding box, and i have tried it with and without models and it still does not place on a block.

I'm trying to make a rope, which obviously I want to fall onto itself to make the rope an actual rope, and I decided gravity might be my best bet, but as I've stated it clearly does not work (although does land on other blocks)