The unlocked version of that phone is likely programed to connect to many different types of LTE from all of the carriers. How the LTE is displayed on the phone itself is different from carrier to carrier for the branded models. For example, AT&T phones will show LTE as just "LTE" on the phone and Verizon Wireless models show "4G LTE" on the screen. Since you have the unbranded model it might use the most commonly used wording/label across all the carriers for LTE.
The phone might also be connected to the Verizon Wireless 5G network which is technically not a true 5G network yet, but is instead more of a LTE+ network.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.