Just to be clear are you having issues trying to add control unit 69 to the car or is it the
coding of the control unit.
With regards to control unit 69 if you go to live data and have an element called SFD activated status then the control unit is SFD Protected, if it does not have this then its not and I did a quick check on a car with one fitted and it does not look like its SFD Protected.
Unlocking of SFD you need to use
OBD11 Pro which currently sells for Eur100 or you can buy an unlock token and use VCDS to do the work.
I know Carista also unlocks SFD but I dont know if you can just do an unlock and then use VCDS to code the changes.
According to the best list of access codes I know about
https://forums.ross-tech.com/index.php?threads/19270/ 20103 is a good code
Is it possible that you have entered to many incorrect codes (you can check this in live data using security access number of invalid keys, if its more than 3 then its locked out and you have to leave the car on for a few minutes till it resets back to 0