My wife has a brain tumor. When we saw the first doctor, he knew it was bad but had never seen something like it before. He specialized in epilepsy and seizures. He was ready to operate even though he hasn’t tackled this issue before and wanted to do a craniotomy.

We felt very unsettled. Went to another hospital that is more renowned for this type of stuff. Saw a doctor. He immediately recognized it and referred us to a doctor who was able to the surgery through the nose instead of a much more invasive head split surgery.

Point is, in your case, if your pulmonologist can’t figure it out, there’s at least some chance that a pulmonologist with a different specialty or training might be able to figure it out or refer you to different tests. Best of luck and i hope you figure out the cause.