It's well known some things will trip those flags, probably not what all of them are or why, but most of them inappropriately (e.g. rating IP trustworthiness, but also simple HTTP requests that look "odd"). It's also well understood you have little to no options available as contacting support, live human or not as it may be, is made intentionally opaque and difficult or completely impossible. They just don't care, there's no reason to when you're one of the many hundreds of millions using their service most likely at no cost, and it's not unique to Microsoft. It's not that they became incompetent (they are, objectively), they simply never cared about you.