今日2018年6月10日、シンガポールでGalaxy S9 Plusにアップデートの配信がありました。
変更内容:
Improved performance – VoLTE, VoWIFI
Dual VoLTE/VoWIFI service is available for both of the SIM cards in the dual SIM slots. (* The service is provided only to dual SIM devices and can still be limited depending on the service operator for each SIM card.)