4.2 bluetooth

[TheOldPresbyope]

I've run btmon.sh and it appears to produce the expected output - both the Samsung Galaxy and Rohan (my OnePlus) paired, but not connected. I ran btmon and then attempted to connect from the OnePlus: the output contains an error message about permissions, see below.
...

So that

Code:

= bluetoothd: Authentication attempt without agent

means the Bluez package doesn't trust your OnePlus. What do you see if you run bt.sh with the -s option?
Here's an example from my moOde installation:

Code:

pi@moode-42b3p:/var/log $ sudo /var/www/command/bt.sh -s
** Scanning for devices (20 secs)
**
** Trusted devices
** 5C:F3:70:89:11:49 T520
** FC:3F:7C:9A:D8:AF Nexus 6P
** D4:0B:1A:19:6D:C0 Nexus 9
**
** Scan complete

All my devices (T520 is my Linux laptop; not another Android device) are trusted and I can pair and connect from any of them. [1]
I don't know why your OnePlus ends up untrusted. You could try to force the trust relationship using the command-line tool bluetoothctl.
What do the command-line tools report when you try to connect from the Samsung Galaxy? is it similarly untrusted?

Regards,
Kent

[1] while horsing around with all my Nexus devices I managed to get into a state similar to what you report. All of the devices were paired, all had previously connected, but at some point I couldn't (re)connect from one. I was able to get back to a working connection by clearing the previous data and going through the pairing/connection process again. Sadly, I didn't use any of the command-line tools to gather information before I did so.