Well, tried everything here with no luck. No, mine didn't take 3s to unlock - it would be unacceptable for me - but it took more time than I'm used to. So, I changed it for a brand new one and... Same thing. Yes, it's a downside of this new and "revolutionary" technology. Now it's time to hope Samsung somehow fix it with an update. Yes, I'm a bit disappointed, since my second device is an iPhone X (lightning fast FaceID) and I'm coming from an OT 6T (fast as can be, too).
Just one curiosity: prior to buy this device I literally watched more than a dozen reviews of it and nobody, simply no YT reviewer, even mentioned this issue. Nothing. Never. Zero words. Can I start wondering how these guys earn money with their work?