this guy whos really my type has been very responsive and showing interest for the past few days and now he isnt really responding

So theres this guy i really find attractive and he seems to even be very interested in me, based on how he was talking to me. He even asked me out to a movie (although I had to reject since the schedules didnt match). Even after then, we kept talking, and he was very sweet/nice/complimenting etc.

We dont go to the same school. but he lives 20 minutes away, so he even told me that he will like to visit me since I am worth the travel and time. That was about 4 days ago.

But now he is not really responsive unless I reach out to him and start a convo. His snaps are still very cute and playful, but it just feels like the intensity we had has been vanishing slowly. Now i am on delivered for hours, but I dont know if I am overthinking this since he told me he is busy with majors this week.

Should I run away? Is this a red flag?