I also have mild bronchiectasis with no or only occaisional symptoms. I've been diagnosed since 2017 and never could produce sputum with the directions I was getting from my local pulmonologist. I finally went to Mayo in 2025 and was taught by the respiratory therapists there how to properly use a nebulizer with aerobika and properly do the breathing that precedes the huff cough. I have trouble and do not like the huff cough but I have been able to produce sputum this way. I rest for awhile between huffs if I don't feel good from it and usually stop after 3 rounds of the procedure series as thats what I can tolerate. Because I have been able to produce and send in sputum samples, I have since been diagnosed with MAC but due to the fact I have low to no symptoms, I do not need to be treated with "the big 3" at this time and my treatment is more vigilant nebs and airway clearance.
I hope this helps you and hope that you can get to a bronchiectasis center that can give you good guidance.