I know this is an old thread and I appreciate you sticking around and updating us. I have had a similar if not the exact same issue with SOB since late 2016. In 2017 I started seeing specialists about it after my GP suggested something was wrong but could not say what. I went to a pulmonologist who ran some breathing tests that showed everything normal except for my diaphragm muscles not working as they should. Because it was a muscle response issue, I was sent to a neurologist because the pulmonologist thought I had ALS. I was very young at the time and the neurologist couldn’t find any evidence of ALS in my muscle movements or blood work. From there I was kicked over to an asthma and allergy specialist, who found that I had neither asthma or allergies, but still prescribed nasal spray. After that, I had given up the search to find an answer and just try to live with it, until I came across your post. Thank you for the exercise recommendation. I am going to look into it and see if it helps my situation.