I'm not even sure if "doesn't fully render" is an accurate description, but in Forms 10, sometimes when we open a process diagram page or the CSS/JavaScript page, some of the page elements don't appear. See screenshot below - you'll note that the "toolbox" items and various other stuff, such as the "Validate" checkbox next to the Save button, are invisible:

The elements are there and can be clicked, they just don't display. No errors appear in the browser console. Refreshing the page doesn't fix the issue, but navigating away and then coming back does.

I've seen it happen on the latest version of Chrome. Haven't tested other browsers, since it's not a critical issue, but I figured I'd make a post here just in case.