If you enrolled but are on the October security patch, you will have to wait a little bit longer before you get the update. There is not currently an update path to beta from the October patch. As for the enrollment banner, it came and went in a matter for 2-3 hours. A new one may open up. We have to wait and see.
So, I purchased my unlocked Note 20 Ultra from Best Buy. Shortly thereafter, I found better purchasing terms through Samsung, so bought a second one with the intent to return the first to Best Buy when I received the second one. While waiting, I signed up for and downloaded the One UI 3 beta on my first device. However, it is unavailable on my new device.
The question is, is my enrollment in the beta associated with my first device, or my Samsung account? I only had a couple of days with the beta on my first device and I'd like to continue to evaluate on my new device, but I'm unsure if I can.