When my s9+ is not on Wi-Fi all my app that use internet doesn t work well. ( gmail, WhatsApp, Viber...) I need to refresh by hand all app and then I receive all the messages or email. Why is that? I changed my SIM card. That is not a problem. Please help
@Dubrovnik88: When you enable Mobile Data (swipe from the top of the screen to the bottom > Mobile Data) are you getting a 4G signal? Have you spoken with your retailer to discuss any restrictions to the service in your area?