I was having the exact same issue about a month ago and getting the same support answeres from everyone over on the ED forum. The bacground story for me is that I had just completed a major overhaul in upgrades for my Simpit and along with that I was making view adjustments and installing MODs others had been using. Somewhere in all that my HUD went nuts. It appeared too zoomed in, the Gun Target Reticle was so out of whack that in a dive it would disappear. In one mission it was at the bottom of my screen in level flight, then was bouncing up and down and went back to normal for a time. Basically the whole HUD view was FUBAR'd. Everything else was fine.

So my biggest complaint with DCS is all the time spent in just tweaking to get it right with good FPS and all that. Anyway, my solution was to do a complete unistall of DCS World. Make sure you even delete the files from your program files folder. If you have any custom files/settings back them up. I started fresh and now all is good. Way faster fix than digging and digging through forums with no good solution.