I used to live in US and got an S9 plus from AT&T. I moved to India (in July 2018), got it unlocked by getting the unlock code and procedure legitimately from AT&T. Put a Vodafone India sim card. It works fine since but I have not received a single update since. Last update is June 2018.
In sw information Service Provider SW version shows
As I use this phone for work, our company mobile management tools prevent the use of rooted phones. How can I start receiving official OTA updates without tempering with the legit status of the device.