The following is extracted from M1 5G FAQ.

Which model of Samsung Phones support 5G SA on M1 network?
Currently all Samsung S21 series supports M1’s 5G SA network.

I have a Samsung S21 series phone. How do I update it to enjoy M1’s 5G SA?
You can update your Samsung Galaxy S21/S21+/Ultra 5G software to support our 5G network using these steps:
– Open “Settings”
– Scroll down and select “Software update”
– Click on “Download and install”

How to know if my Samsung S21 series is updated to the latest software to support M1’s SA 5G?
You may check on the latest software current version which should indicate G99*XXU3AUG4.

How to check if my Samsung S21 series phone is on 5G SA mode?
Once you have inserted the new 5G SIM Card, go to
– Phone Setting
– About phone
– Status information SIM card status
– On the Mobile voice and data network it should indicate NR SA under Mobile voice network type and Mobile data network type.

However, If you do not see NR SA indicator, you may follow these steps:
– Open “Settings”
– Select “Connections”
– Tap on “Mobile networks”
– Click on “Network mode”
– Select “5G/LTE/WCDMA/GSM (auto connect)”

I have an overseas S21 phone and will like to use in Singapore to enjoy M1’s SA 5G experience, can it support?
You are encouraged to purchased local variant only in Singapore to enjoy M1’s SA 5G.

How do I know if my handset is local Singapore?
Please check with Samsung customer CS hotline 1800-4252997.

By Harry