Originally Posted by
Speedldew
Appearently I lack some core stability in the neck/shoulder region so that my muscles can't quite support the aggressive position, yet.
And, of course, doing some more core strength training for neck and shoulders.
My feeling is that this might resolve itself as more riding is done.
This is based on my own neck which got quite thick and muscular when I commuted 12,000 km/year on a road bike. In 2018 I rode nearly 8000 miles and much of that on rough gravel. Small gains in upper body mass and lots of definition, especially in the triceps, were noticeable in the mirror.
I'm not saying to ride through the pain or ignore your health care provider but only that it will might be temporary if you have not ridden a more aggressive drop bar bike and go away as your body strengthens.
-Tim-