On Septerfon, location [80, 171, 771], on a set of sedimentary stone cliff faces, it blocks me from running into a hole i make.
I try to run into that hole, 1 wide, 3 tall, and it blocks me, and i start gaining a little bit of height for no reason. I haven't had this problem previously when i've mined these cliff faces. but today 3/12/17 i have.
i tried making it 2x3 but it still happened until i jumped. i dont know why.