Our project is facing issues of this kind:
However, while not having access to the source code of the 3rd-party lib which we wish to use, we do have a static version of it.
It appears that .so files inside Plugin/Android are magically copied to the appropriate place in the final apk, but dropping a .a file there does not mean it is included in the link command generating il2cpp.so.
Is there, by any chance, a way to let Unity know about static libraries to be linked against?