I'm a senior college student. I'm struggling to recognize a pattern:

At some point during the semester, girls I've been casually talking to will give me plenty of IOI's during a certain conversation. After this conversation, things get weird: the girl won't approach me spontaneously anymore, might look at me from a distance when I enter the room or something. When I DO approach them, (which is difficult since they'll surround themselves by friends) they are unreceptive and seem uninterested. At least a lot less receptive and interested than they were during that one IOI conversation.

There's probably something I misunderstand here concerning the Push/Pull concept: is this concept only applicable during a conversation, or should be also applied in the bigger scheme, as in "I approached you last time and gave you plenty of IOI's, the ball's in your court now, do something with it", because this is the vibe I'm getting. It's like they expect something from me after they've shown me their interest, but whenever I try to do something (aka game them some more, escalate and ask them out), they won't let me.

It all feels like a big shit test I don't know how to handle.