Is there a way to enable hotspot / tethering for the Nexus 5X and 6P even if you don't have a subscription plan for it? How do you do it via rooted phone and a non-rooted phone?
This is the only "fix" that has worked for me thus far.
I switched from the Nexus 5 to the 6P yesterday and discovered that my grandfathered unlimited data plan was of not much use now because the Wifi hotspot functionality has to be activated through the carrier on the 6P. Wifi Hotspot tethering worked just fine on the Nexus 5.
At least I can use my hotspot, but this pop-the-sim-card-out work around will get old fast... Oh well :/
(tested on 6.0.1 on 2016-05-10 and 7.1.1 on 2017-02-09)
adb shell settings put global tether_dun_required 0
You only need your sim tool and the phone.
Works for Verizon and AT&T. I have not tested this on any other carriers. This works by turning on the hotspot while the phone is provisioning. If you attempt to do this too soon or too late you will trigger the subscription check. You will need to perform this everytime you want tethering if you turn tethering off or reboot the phone.
This also appears to work with the Moto X Pure Edition using Straight Talk. Slightly modified steps, though. Eject SIM tray, turn on tethering, Push in tray.