Hi there,
What browser you’re seeing the title size issue? I can’t find it and it’s normal since there is a parallax effect that moves a layer from one position to another, it’s moving from left to right, hence, clipping to the right will occur. It’s similar when it’s moving from outside the slider (started hidden/clipped) and fade within slider viewport.
About the missing slides on mobile, I went ahead and fixed it.
But you must enable custom grid and customize your layers in mobile view. https://www.themepunch.com/faq/incorrect-position-or-size-for-text-button-or-shape/. It doesn’t look okay as of now.
Cheers!