No acid reflux or other issues that my medical team has discerned. Recent CT scan showed no signs of infection or other issues. Clear, sticky mucus is constant (right upper lobe). I get relief from laying on my left side. (Some days are better than others, but otherwise I feel really good.) Prevailing opinion is that I had “something” that caused this. I did have very severe Covid symptoms back in Nov / early Dec. I probably should have been hospitalized but toughed it out at home ... lingering mucus could be a long-hauler issue. Another opinion is that I encountered a chemical of some kind that has irritated that lobe. My instincts (yes I listen to them sometimes) tell me that this mucus issue could be with me for a while, but it does seem to be improving very slowly (Sue’s comments about her and her daughter’s lingering mucus issues hit home for me). I’ve been riding my bike many miles without breathing issues and energy level is finally back to normal.