When entering anything into the address bar and hitting Return, nothing happens. Trying to either go directly to a URL or just entering a search term results in no action happening. Sometimes hitting Refresh will load the page requested, but that does not work if searching for something. Also, it looks like the auto-complete in the address bar is not returning results.
Could you please report this via https://bugreport.apple.com? This issue could well be outside WebKit, and Apple bug screeners are better equipped to look into such issues.