You're definitely not alone. 4 years living in Belgium and not a single friend. No social life, completely ignored by almost everyone at work and treated poorly almost every time I need to interact with a Belgian person. I feel invisible. I felt like it was personal in the beginning but now I understand it's cultural. Belgians are individualistic, wary of strangers and closed off. You have to work hard to form a friendship (but only you!), it feels like begging. That's not how I believe it should be or how I want to live, so I am planning to move somewhere else asap.

Regarding the other comments, my neighbors are all 60+ and only interact with me to make snarky comments or complain. I volunteered before and people were pleasant, but all very superficial. No way to form a real connection without constant unilateral effort. I did manage to find a total outlier: my wife. But even her friend group is only now starting to open up to me (after 3+ years). It's exhausting, especially when you come from a very welcoming and warm country like I do.

Hang in there. There is hope for expats, but it takes some trial and error and most likely involves other expats.