I use Badgers, once a friend loaned me one of his to try and when I used it there were bubbles in the cup. On close look I saw the nozzle, (the little cone shaped part that the needle tip passes through,) had a small split. Replaced with new one, worked fine. I believe your 200NH and the 155 use the same type.
If you have your manual handy, its either part 41-004 or 003, depending on the needle size. Also might be a bad seal at the different front bits. Bees wax or Chap Stick can help to seal a bad fit. Sounds like you have sufficiently cleaned, so those are the things that come to mind.
Using very high magnification look closely at the nozzle ends, they are very delicate and don't take well to force, they require gentle handling. If there is a split it will be very noticeable.
Last, have you had a good look at "Don's Airbrush Website" yet? He covers your airbrushes among many others, plenty to be learned there, highly recommended.
Best of luck getting it sorted, please let us know how you do.
Patrick