If you believe even the worst version of rumors (which there is barely any proof for) she had a total amount of 3-5 boyfriends (they can't even agree on this) and may not parted ways with some of them before hooking up with others. Which doesn't sound particularly weird for a college girl, but if you remember her talking about how she was afraid of being weird in front of her friends and did a lot of things to fit in with their group and hid her real interests and hobbies, may not even be something that she wanted to do in the first place. Only having a boyfriend to have a "not single" checkmark and dumping him or ghosting the moment he tries to get physical is pretty fitting for how she described her college life, and for an autist like her