There is an issue regarding navigation with history inside an iframe, removing and appending an iframe dynamically and the Webkit version that ships starting from Safari 12. This issue is not existing in previous versions (from what I've tested), and it's still present in latest Safari Technology Preview. Here's a link that shows the issue and the steps to reproduce it: https://jsfiddle.net/rhon4bvk/3/show. Notice how the history gets messed up after removing and appending an iframe, and how performing certain navigations forces a refresh of page. Also notice how this doesn't happen in other browsers, like Chrome, where the behavior the second time after closing and opening the iframe is the same as the initial one. The code for the outer page is here: https://jsfiddle.net/rhon4bvk/3/ The code for the iframed page is here: https://jsfiddle.net/Lnr3q809/3/
<rdar://problem/50825679>