Yeah, been there. I once assumed a formal handshake was standard, but a more casual greeting was actually expected and it threw off the whole vibe at first.
Greetings are just the tip of the iceberg. I saw a guy bring a gift to a meeting where it wasn't the norm, and it created this weird pressure to reciprocate. It shifted the focus from the deal to the stuff. Now I do a quick search on basic gift-giving rules or if meetings even start on time. In some places, being five minutes late is polite, and showing up early can be seen as rude. Getting that wrong can set a bad tone before you even sit down.