It seems you are right about pairing mode.. I do not need to change the discoverable state. I was under the impression that I needed to re ‘OPEN’ every time the connection was lost. However, it looks like the source will automatically re-‘OPEN’ after the headset powers back on. (yay!)

I’m still noticing the same failure though :(… My updated procedure is as follows:

1. instead of issuing “call 13 end”, i’m pulling power on the headset device and waiting until the source device receives ‘CLOSE_OK …’ to indicate that the connection is lost.

3. plug power back into the headset device and wait for boot

4. on the source device i wait for auto-reopen message on UART: “OPEN_OK 12 AGHFP …”

5. on the source device issue “call 12 incoming”

6. on the headset device issue “call 13 answer”

Note1: I am testing on latest release 3.1.70D:
“`

IOT747 Copyright 2022
AudioAgent IDC777 V3.1.70
Build: 0400427b
Bluetooth address 245DFC0201AD
Ready
aptX Lossless: ON

“`

Note2: Recall, the issue is ONLY present when one of the devices fail to end the call “call 13 end” before power cycling! You suggested: “As long as you do the CLOSE 13 END”. This is not an option in a power loss senario.