I have the MOTO Z2. Its a pretty decent phone and I don't have any issues other than this: When the phone goes to sleep (black screen) and I say "OK Google" to wake it up, it asks for my passcode to continue. I already know that in these circumstances you must:
1. Go to Security & Location > Trust Agents > Smart Lock and turn it off
2. Reboot the phone
3. Go to Security & Location > Trust Agents > Smart Lock and turn it on
This will allow it to work for maybe 48 hours until it loses its mind again. Sorta counter to the "hands free" mode.
I just upgraded to Android 8. Guess what? Its still broken exactly the same way! Perhaps I am missing something that could correct this? Any suggestions?