I am having same issue. Was told in 2018 that I was just below 50% trachea collapse and could not diagnose with tracheobroncholamachia yet. That was at National Jewish Health in 2018. Since then everyone I have asked about it just ignores me. My PFTs show a blockage slowly gettinb worse but because CT looks normal they just keep ignoring. My Rheumatologist said a CT is not the right test to see it and have to go in and actually look at it, but no one wants to acknowledge the problem could be trachea collapsing and order what needs to be done. Meanwhile my O2 levels on pulse ox now dip into high 80’s.