Baby chokes on milk until shes blue

So i wanted to ask if anyone has had this happen to them. My LO is currently 5months old turning 6 she is a super happy baby rarely cries(we joke that she doesn't know how to cry because when she does it sounds fake).

But ever since she was about a month and a half she does this thing where she chokes on milk and thats fine, because all babies choke on milk. But she doesn't cough it out. It always gets to the point where shes blue and about to pass out.

We went to the doctor after it started happening she sent us to the hospital where we stayed for a week. They observed how she drinks and thats it. All they told me is that it might be reflux. No other explanation. No tests nothing. They did give me the booger sucking bulbs and told me if that doesnt help call 911.

Shes almost 6 months and it still keeps happening tonight i thought would be the night we would lose her.

I just wanted to know has this happened to anyone else. Is it common. And will this ever stop because i cant live in this panic all the time.