Version is 2019.2.6f1 I have a floor which is made up of 16x16 tiles, each tile counting as a 1x1 block. I also have a BoxCollider2D representing the test "hero" who can move side to side and jump very high. It seems there is a bug with Unity that causes a BoxCollider2D to just smash through a TilemapCollider2D at high enough speeds. It doesn't happen every time but it's pretty frequently. Never happens at lower velocities. Gravity is the standard value but velocity is high due to the object falling for a good 8 seconds or so. I can reproduce the issue 100% of the time, using a slightly tweaked version of my project.