First thing's first - the outline around the hair is weird. Could just be 'portrait' mode in the camera. I don't suspect it's AI

Second thing - here's the instagram account for the restaurant. Ask them if they know the guy.

What did you use for Reverse Image Search? Google Images sucks butt now, but I've had good results with Tineye. Thing is, it could be a private Facebook account that they've pilfered images from, and that's not going to turn up on reverse image searches.

Also, it's 2024. Get on a fuckin' video call and say hi face to face. Can't do that? GTFO.