Sprite overhanging platform

Hi I am new to GDevelope, I am trying to create a simple platform game, My Sprite over hangs the platfrom blocks / bricks,
I have changed the collision mask on my sprite (to a thin strip through the middle) and even changed the collision on the blocks to 1/2 its width, but my sprite still overhangs in either direction, is there a fix for this ??

also how can I make a bullet ricochet?

Look forward to hearing any ideas