I don't know about anyone else but I have found APM 2.5 to be very buggy. After several attempts at creating a new monitor on my NPM server I finally gave up and contacted support. Although the tech was helpful the end result was the same, I did what he suggested and moved the NPM installation and all of the modules to a separate server from my database and attempted to create a new APM monitor.
Guess what it didn't work! I got the same result, keep in mind this was a fresh install with no alterations to the default configuration. I found that pages don't always load, script errors are pretty common, and that the application outright behaves erratically.
I know this is of no value technically to anyone on this board but it sure helps my mental state to vent, at least when you buy a car for 40k and it don't run you can bring it back. 