Ok I've gone ahead and got my old galaxy s3 out.
Went and purchased pro app
It's terrible!! It connects only 1 in 100 times.
I've gone through all troubleshooting but in the end I'll just scan 100 times and it might just work once.
Has this happened to you?
I emailed them there to ask for advice.
This has happened both on my car and my gfs golf 1.4 mk5