I had this problem with my Galaxy S5 Sport, but after playing around with my settings, I figured out how to get my phone to ring normally without cutting or muting out, or "jumping." In "Quick settings" select "Sound." Under "Ringtones and notifications" check the box for "Vibrate when ringing." Then, if you're like me and don't want your phone to vibrate when it rings, select "Vibration intensity" toward the top of the menu, and there you can adjust your vibration settings from full to none. This fixed it for me. The first ring is still soft but the rest of them come in consistently at regular volume. I hope works for you too!