Yeah, the OBD adapter never gets a BT icon to show it's connected, only the phone gets it.
I never got very far with BTTether, as my last phone (and even my current) don't support it. Killed by the carrier it seems... But there were a couple of threads somewhere in here about using it.
Good to know about the icon.. that is one less thing to worry about I guess.
It doesn't seem like bluetooth tethering is such a big ask.... bloody manufactures should have to tell people they have stuffed up base features in android in their units. My phone is a pixel 3 XL with android 10 and I can verify it is actually offering internet over bluetooth, I just can't route the Joying to use that connection as it's gateway... It's annoying because wifi tething chews my battery life and I'm already connected to the unit via bluetooth for call features. I might read up on how BT tethering works.. perhaps it's possible to use a self targetted VPN type app like DNS66 to trick the OS to use it as a gateway without breaking existing functionality.
I removed BTteather as it either didn't give me any feeback that it did anything other than turn off the wifi or it didn't do anything other than disable wifi...
I'm a linux admin so it's weird to feel powerless on a box we have root on...