Hi Phil, it's a cool shirt, maybe you could consider some of these tips:

The issue you're experiencing with your State & Liberty dress shirt may be due to the stretchy and athletic fabric used. Here are a few suggestions to help fix the problem:

1. Ironing: First, try ironing the collar and the area around the neck. This might help reset the shape of the collar and make it stay up better.

2. Steam: Use a steam iron with a cloth or press cloth over the collar to apply steam. The heat and moisture can help relax the fabric and restore its original shape.

3. Water: Dampen a cloth with cold water, wring it out, and place it on the collar. Then, use a warm iron to apply pressure over the damp cloth. This should help loosen up the fabric and make it easier to adjust the collar.

4. Stretching: Gently stretch the collar in the opposite direction of the collar's current curvature using both hands. Hold for a few seconds before releasing. Repeat this process a couple of times to see if you can restore the original shape.

5. Sewing: If none of the above methods work, consider sewing a small dart or gathering stitch at the inner edge of the collar where it meets the shirt's body. This will help keep the collar in place and prevent it from sagging.

Remember to handle the fabric carefully when attempting these fixes, as stretchy fabrics can be delicate. If you're not comfortable trying any of these methods yourself, consider taking your shirt to a professional tailor for assistance.