5G UC Icon not showing on Samsung Note 20 Ultra

And different carriers and manufacturers display the same levels of service differently.  There isn't a standard that requires the icon to say 5G UC when 5G in most cases, is all people will notice.  Just look at the mess with 4G, 4G LTE, LTE, LTE+, etc.  Just like how the number of bars for signal do not accurately represent the signal strength because there is no standard for that either and how many bars are shown for X amount of - dB is literally up to the OEM and to a lesser extent, the carrier to specify, and they do vary significantly by device and even firmware.