How to fix Safari's html margin bottom bug in iOS 10.3.1
You can use this:
min-height: 100vh;min-height: -webkit-fill-available;the second line will push that element to fill the screen.
Here's the more about the hack: https://css-tricks.com/css-fix-for-100vh-in-mobile-webkit/
Lately, I experienced a similar situation with a Cordova WebApp and iOS10. The issue was back then, that the main view-container had a height of 100% and not 100vh. Take a look at your CSS or update your post with more information.
I had a similar problem with a canvas element that took up the height of the webpage but had some whitespace underneath it when I scrolled. I set the canvas to display: block;. This solved the problem for me. Here is the question that I asked why is there white space under the canvas when I scroll down. Try to change the element's display property to block and see if that helps.