If we have more than 1 account in SmartOne IPTV app, it will load the first one in the list, if we want to set a custom account as a default account :
1 - Open SmartOne IPTV APP
2 - From Main Menu Goto Settings,
3 - Goto Accounts
4 - Select Account and press BLUE button.
now, when reload or lunching the app, the default account loaded will be the selected account before.