Riding Position and Neck Soreness

I’m new to triathlons having started about 1 year ago. Having a great time with the sport. I’ve put on about 1500 miles on my road bike so far with little problems. I was professionally fitted before and after I bought my (used Specialized Allez Elite 61cm with clip on aero bars) road bike. I’ve always felt that the bike has been a bit too big for me and I’ve been tinkering with my bike and position in an effort to make it fit better and for me to ride more aero. I went to a shorter stem and it felt better. Then I went with a fast forward seat post. That’s when the problems started. Immediately, I got a sore neck. The kind of soreness you get if you wake up having slept on your pillow wrong. Could only turn my head to one side, etc. I was bad enough and lasted long enough that I eventually went to a PT to get my neck back in line. Went back to my regular seat post, neck soreness eventually went away. Put the FF seat post back on and the neck problems came back. Soooo, I feel pretty certain that the FF seat post is the culprit. My questions are: Anyone else experience this? Is there anything else that could be causing this neck soreness on the bike? Any other general comments on bike fit, body position and neck soreness? Thanks.

What else changed with your forward position? DId you also go lower on the bars?
Step 1 try raising your bars a tad so you don;t have to lift your neck as much to look down the road in front of you!

I didn’t mess with the raising or lowering the bars, though I did have a Triathon coach and sports medicine guy tell me to lower the bars to stretch me out more. His opinion was that my neck was no longer able to stretch out as much.

I got some soreness when I moved my arm pads in a little too close so that might also contribute to what you are feeling as neck pain. Also, if your position is a steeper that means your neck muscles (which are pretty weak) have to hold up the weight of your head and helmet in an awkward position. I imagine this takes awhile to build up no matter who you are.