I have had this camera for a few years and it worked perfectly until I upgraded the firmware last year. After the upgrade I could not log in using the app, however the web interface worked ok.
Despite many calls to support the problem could not be resolved. I decided to go on a mission to find the previous firmware. it was not available on the Amcrest support site.
I eventually found it here.
http://drivers.softpedia.com/get/networ ... 006R.shtml
I downgraded the firmware and access via p2p is restored.