Need help getting a ramp/inclined plane to work with Paper2D

My character is running around on a platform, hooray. I wanted to add an inclined plane (aka a ramp) for him to walk up to get to the next plateau but have run into some trouble. I plunked my triangular shaped sprite down on top of the platform such that the player would run up it just by holding down the move left key. Instead of running up it, he just stops as if it were a wall. I’ve edited the collision to also be triangular to match the sprite’s visual. I can jump on top of this ramp and he’ll slide down it (which verifies that it’s not a wall and the geometry is working as expected) but I can’t just run up it from another platform. Why would this be and what can I do to fix it?

Also, how would I change the properties of my physics surfaces? Like if I wanted to alter the friction of the ramp or the platforms? I made a physical material but don’t see where I’d hook that up to a Paper2D sprite. Thanks!

Edit: I should note that I didn’t change my physics, so it’s still using 3D physics (like the new 2D platformer template does).