I run in the same paradigm when I try to create a static linked library with Qt targeting Android and latter to use it with JINI on Android Studio.
Reading you post I see you have almost the same problem like me with one difference.
To me are working as far I use only std library
My problem appears when I use QString for example in the library.
Looks the static build does not statically includes the Qt framework dependencies.
Finally did you find a solution? Me I run with this issue past over one month.