After one of the updates even before Oreo came out, tethering stopped working (wifi, usb) on my nokia 6 2017
I can't take credit for the fix, as I found it online, and I lost the reference url
settings put global tether_dun_required 0
To confirm it worked, type this and press return:
settings get global tether_dun_required
It should print out a zero.
before doing so, I ran "settings get global tether_dun_required" to find out it returned "null".
after executing the commands, tetheting works like a charm for me
*what still missing is from nokia 6, it still not listing any connected devices
hope it helps some of you!