Some guys are just extra shy and awkward during the first physical meeting.

I've had my fair share of such experiences. Guys are more natural, at ease, and expressive in online chats and video calls, but they get quieter in real life when they meet the women they like. They do get extra self-conscious and spend more time listening and observing than talking.

I suppose you like him a lot, and hence, you expect him to behave the same online and offline. However, from his POV, he may just be feeling uneasy on the first date. Flirting with a non-GF-yet in real life does take some guts, especially if he's an introvert.