iOS 12 KeyboardShrinksView keyboard dismissed on WKWebView

[byronigoe]

The normal window.innerHeight and document.documentElement.clientHeight on an iPhone XS are 734. With KeyboardShrinksView enabled, opening the keyboard resizes the view perfectly on iOS12 with WKWebView. However, when the Keyboard is closed/dismissed the view resizes to 812 instead of 734, which makes the app look like its height is very small (maybe 812 % 734 = 78px?).