What code are you trying to use? I frequently use *#2263* to change my bands when 5G takes a **bleep**. I did notice that our note 20 ultras have a 2nd Sim option in that menu for a web Sim
I am having issues with USSD codes on my Note 20 Ultra. I can do non transactional USSD operations like checking my airtime balance successfully but when it has to do with transactions like checking bank balance, buying airtime it spins for like 4 minutes and says 'try again'. I Have complained to my service provider, they say everything is fine because when they put my sim card in another phone, I'm able to perform any type of USSD operations.
