I had numerous tight hip muscles that caused my firm flaccid. Try to stretch the piriformis, iliopsoas and buttocks and see if you have for some reason developed bad posture or bad sitting position. Dealing with these issues cured me. The muscles in spasm require long stretches, for example, opening up my piriformis muscles took about two weeks of regular stretching. However, if you have none of the above mentioned issues, I believe the cause of your firm flaccid is not the same as mine.