I've found 2 bugs related to version 4.1.4.
When you use viewport units to setup full screen element, it causes strange infinity behaviour of preview.
The element (that with 100vh) becomes infinity tall and you can't actually see any what's below.
When background-attachment is set to fixed, it renders preview that doesn't follow background-position & background-size rules at all.
I think we might need to know more about #1. I created a new project and then added the Hero Food component then set the
.jumbotron.hero-food element to have a
height:100vh. It did not infinitely grow the height. It filled the viewport and that was it.
It might help if you gave us some examples of how to go about reproducing this bugs that would help us to see if it's just an oversight on something or a true bug.