Family Map is USELESS

I have family map so I can locate my one NON-iPhone device. it's a ZTE Maven (Z812) on my post-paid account. It located it ONE time, and hasn't ever been able to again. No matter if the phone is on wi-fi or not. No matter if it has GPS turned on, or locations set to battery saver. Nothing i've done will let this phone work on Family Map. I have been reading on the forums and elsewhere that Family Map doesn't work on non-iPhones. What's the deal here?

***UPDATE, if I turn the phone's DATA off, it locates just fine. So evidently it WON'T locate a phone that is connected to the AT&T LTE data network. What's the deal with that? How can AT&T sell a feature that won't work on 99% of their phones unless you install and run the family map application. That is the WHOLE point of parental controls and location verification.