I have this confirmed as a core bug which we hope to fix over the next few weeks.
Specifically:
[url]http://example.com[/url] will work however: [url]http://example.com/example[/url] does not unless you add a trialing space [url]http://example.com/example [/url] .
I started stepping through stuff and it looks like something is tripping our parser here, possibly an escape rule. We will get this sorted, thanks for raising it.