As explained by Chris in his self-answer, calling
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR);
and then
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR);
really works like charm… on real devices !
Don’t think that it’s broken when testing on the emulator, the ctrl+F11 shortcut ALWAYS change the screen orientation, without emulating sensors moves.
EDIT: this was not the best possible answer. As explained in the comments, there are issues with this method. The real answer is here.