Hi again, , and thanks for your post and question - it's a good one. I am sorry to hear your medical team are not agreeing on your diagnosis. It should be clear to whichever doctor is your main / lead / pulmonary physician. There is a rather well established method that results in a definitive diagnosis for patients or, permits the doctor to 'rule out' the diagnosis as well.
I thought you might gain some additional insight for what diagnosing COPD entails from this article: https://copd.net/diagnosis. I do hope you find this information is helpful for you in a practical way.
All the best, Leon (site moderator COPD.net)