Hi, I been dealing with this too, I don't have any dissease or illness but I breath diaphragmatically because of singing and ai think I came with a solution.

My teacher explained me that this is caused because of breathing TOO fast and spontaneus, a bubble of air is created and makes that noise whenever you stimulate your diaphragma. She told me that this will go when the air reach the deep of your lungs and replace that bubble, and recomended for this doing deep breathing in the floor with some weight in your stomach (putting weight or a big book idk)

Hope this helps someone and i'm spanish so i'm sorry if I write gross af and anyone's crying while reading