AT&T has started pushing out a new update to LG G5 and LG V10 units on its network. Arriving as build number NRD90U and MRA58K, and weighing in at 67MB and 57MB, respectively, the update brings Android security fixes for March. Given that the roll out has just begun, it may take time for the update notification to pop up on your device. You can manually check for the update by heading to your handset's Settings menu. Source 1 2 | Via
Source: http://www.gsmarena.com/lg_g5_and_v10_on_at_t_getting_march_security_patch-news-24171.php