Playing holes 3, 2 and 1

Hello DavidA, welcome to the harmonica and to the site. Training your tongue will take some effort and time. As you go to brush your teeth each day, open your mouth and work on lowering your tongue in the middle and back. We think that we're lowering the tongue when we can't see it (while we're playing), but commonly it's not. By opening your mouth, lowering it, and seeing that it is lowered (or doing whatever is required to actually lower it), you're training your muscles and visually confirming what you're doing is correct. When placing the harmonica in your mouth, focus on not raising the middle and back (the front will slightly to tongue block). Give this a try for a week or so and report back.