animate frame by frame (newbie)

Hello everyone,

I am having a small problem with animate, and it is very possible it has a very simple and easy solution, so please bear with me and my ignorance... I want to draw a frame by frame short animation, or even import the drawings from photoshop or illustrator, say something like a bouncing ball. My problem is that whether I import the images or draw the actual ball on each frame, when I play the animation, all the frames remain visible until the end. In the best case scenario, I have had the very first frame visible throughout and the rest playing in order, but I haven't been able to reproduce that "success" again. What am I doing wrong? All the frames are keyframes, followed step by step tutorials on youtube of people doing the same, and their bouncing ball disappears after it is played frame by frame showing movement as it should be... I would really appreciate a little help, thank you very much.