After installing a module, or plugin on any website I work on, regardless of the type of software, will close the browser, clear the cache and cookies, and then replicate the experience from an external user seeing the site for the first time, to test the feature.   This avoids many problems, and while slightly annoying, also solves many problems too.  :-)  

But yes, I understand where you come from on this.  In my case, after doing what I usually do, described above, the feature did not perform correctly, but I did clear una's cache before I exited, and cleared my browser, so just submitted this previous comment in case it is somehow helpful.  :-)  Perhaps the file had not updated itself inside of OPCache (APC) yet.