So, I've been having this problem; I want to use Trusted face on my HTC One (M8) stock Android 5.1, but in Smart Lock, only these options come up:
- Trusted devices
- Trusted places
- Trusted voice
- On-body detection
The option for Trusted face, isn't there, not even grayed out. In my Trust agents, Smart Lock (Google) is activated.
The only things I have done to the phone is root it, install TWRP recovery, and changed the DPI from 480 to 430. I don't think any of these are causing the issue, as I tested the default 480 DPI, and it was working fine on Lollipop 5.0.1.
Anyone know how to fix this? I'm going to perform a backup via TWRP, then factory reset to see if the feature is back, I'll keep you all updated.