Hello ah007
I have the same issue, and I found a solution
But, because I don't have time and the tools to do it, I really can't tell if you it's gonna work
I read that works, but nobody who have the same problem tell me if works
Just put this title in the search bar of the page
[Noob-friendly] Goldcard SPL Downgrade Method; No Android-Phone and/or custom wires!
Let me know if it reach the goal
And, I have a question for you
Do you have strange problems when you lock your phone?
I mean, unresponsive screen or something like that
I have this problem
Hope my answer works for you
"Live long and prosper"
DFLC56