I can't recreate your problem, but looking at your capx, I see a lot of things running every tick that don't need to be.
for example, if A key is down, you are setting mirrored, setting an animation, and setting an angle - all every tick that A is down. all of those things only need to happen ONCE - the moment the A key is pressed.
A lot of those things running every tick will translate to your game slowing down and in some cases (setting the animation, for example) will cause things not to work the way you want..
So my advice is try separating the things that only need to happen once from the things that do need to happen constantly, and see if that helps.