What you encountered is someone bought the real one, swap the fake one, return it and you bought it Fake S24 Ultra is extremely well made, I watched many videos on Youtube and most of the time I can't tell the differences between a real and a fake one Also, please remember that the "Visit the Samsung store" doesn't mean it sold directly by Samsung, the phone still sell via some sellers More on reddit.com

Yea I would say go with Samsung. I bought a return from Best Buy and the fingerprint is not working correctly. There support sucks too. More on reddit.com

I bought an Amazon refurbished S23 last month and had it for 2 weeks. The phone was excellent. I flashed factory unlocked firmware on it and set it up exactly the way I wanted. Was at work. My wife went to Bestbuy and bought me a new S24 and convinced me to return the phone. My wife simply didn't trust using banking on a refurbished phone. She was convinced it had malware on it that couldn't be removed even with flashing new firmware. The phone's manufactured date was March 8 2024. So the phone was practically brand new, but I do love the S24 and my wife, so the phone went back to Amazon. I paid $385 for the S23, 128 version, Snapdragon version. She paid $779 for my S24. It's the 256 version, Snapdragon version. Check the manufactured date on the phone, also check battery health and how many times the phone has been charged. More on reddit.com

You understandings are correct. You can change to unlocked XAA csc to make it unlocked by flashing U1 firmware. More on reddit.com