Hi CM5f14f6, and welcome! I see you are a new member here having joined earlier today in the morning. We are so glad to see you already becoming engaged with the community with this, your first post.
I do have something to say in regards to your question which, by the way, is a good one! The answer is yes, for certain!
You may be aware that asthma affects everyone differently. Having said that, medications, too, can vary in terms of their effectiveness for each patient. There are some patients who do well with certain medications and medication regimens, while still others, do not. There have even been some patients who have had adverse reactions to some medications, which then have to be stopped. Perhaps, that is what occurred in your case.
I am very glad to hear that once the medication (Trelegy), was stopped, your asthma actually improved. You must feel very good about that! However, I am sorry to hear that your physicians (the allergist and the primary care physician (PCP)), would not discuss this aspect of your medication regimen with you. Are you satisfied with the care provided to you by these two physicians?
I do hope this brief reply was helpful for you.
All the best,
Leon (site moderator asthma.net)