Unreal Engine can be in another drive (I have it in another) but I seem to remember that all the Android Studio part has to be in the C: drive, I have all the Java and Android in C:.
It is very possible that this is the problem, I think it happened to me and I saw it somewhere that it was totally necessary.
Let us know if this is the case.
Use UE version 5.1 better; 5.0 is buggy.