My Settings app's screen goes black for a few seconds, frequently when I'm in the app management area of my device, an Asus Z8s Zenpad (Android 7.0). I could tell you all the symptoms of this device, but it'll be quicker to know how to determine if Man in the Middle (MITM) is the issue.
I have tried ESET, Sophos and several other antivirus programs with no luck. I performed at least ten factory resets / hard resets. The device has not registered any of the resets.
Can you provide a layman's rendition of those steps for determining if that's the case?