Here is the process that Surgey has discovered that will fix the pairing issue if it is related to a fault Boot Loader. There is a lot of information provided but I believe that it is all relevant to the process and should be taken into consideration.

***watch this video as well***
   • GoPro Karma SD boot - nothing shows i...  
We have changed the process slightly after seeing some SD boot issues

This video explains why I don't believe the NAND is saturated and requires replacement.
   • GoPro Karma NAND Saturation - Why I d...  

This video is the same process but with a board missing one of the FB36 pads. It has a few close ups so you can see what I am doing.
   • GoPro Karma fixing the pairing issue ...  

The SD card image and burning tool can be found here https://drive.google.com/drive/folder...

These are the commands that are used within Putty
At the login prompt use the login name root

insmod /opt/sentinel/modules/mtd_write_enable.ko
dd-new if=/dev/mtdblock0 of=/home/backup/mtdblock0.bin conv=sync,noerror status=progress
flash_eraseall /dev/mtd0
nandwrite -p /dev/mtd0 /home/orig/mtdblock0.bin

I have also included the invite for Discord which can be used to ask question and obtain other information. It also has a sales section for parts as well as broken and working Karmas. It includes a section when people can let you know (hopefully with Country and state details) that they can carry out the process for you (assumption is that it will be for a fee).

  / discord  

Here is a list of people who can help in different countries

https://www.facebook.com/groups/60999...

This process will not be within everyone's abilities but with the knowledge of what needs to be done it provides you with options.

Sorry about the dogs barking in the background but they are not mine.