Although reading some of the posts here, I often wonder if we are all talking about the same thing.
So, if this is ANYWHERE. You have the ability to connect two gizmos In my case I use them to watch my t.v. package on my pc & laptop
If you have a mobile, you will probably have to download an app. Via a pc \ laptop, you merely watch via A BROWSER, I say ''A'' since if you swap between browsers, you'll use up the option to change either of the two slots, of the monthly change (restricts changing frequently) So I've come to the conclusion there is a cookie loaded \ rather some mac address filter.
So TWO slots, with a restriction of 28 day changes - this is where, if you constantly try to sign in, particularly with apps & different browsers, you will use up those options and need your account reset. Effectively you have used up your options and locked yourself out.
Sign in ok. Even get to view listings, control Tivo box etc etc. When I select a channel to watch on my phone it gives option to register device. When you click register it comes up 'access denied'. Never registered any devices so am very confused. My S7 has just been updated to android 7.0 from 6.0.1.