Verizon have begun rolling out the AUB5 update on their Snapdragon, carrier locked. S21 series phones with the March Android Security patch.

It is a FOTA, (Firmware Over The Air), update and you can check... Settings > Software update... to see if it is available for you.

Build date = 24 February 2021

Release date = 04 March 2021

Android Security patch = March 2021

This is the 2nd stable update in 36 days