I don’t think either are suspects unless of course your shoulder moved like this before the recent issue. Hearing a crack indicates an acute injury, even if on top of a longer standing deterioration of a tendon like the supraspinatus. You should not be training at all on the shoulder until it’s accurately diagnosed as right now the movement is dysfunctional and will lead to other issues (like a ‘frozen shoulder’ type scenario).

An MRI would be the best option. A dynamic MRI even better.