I have been having this issue on and off since I bought my Galaxy S9+. Like most people, when they go into an area with bad service, they do not recieve calls and text being that data is off in that area. The problem I have is when I leave these areas, my data still doesn't work, even though I have a strong cellular signal. The only solution I have found is turning my phone on and off or going into airplane mode and back. My phone does not reconnect automatically like most cellphones do. Its become pretty aggravating when I don't notice that I am in an area with bad service and upon leaving and moving around all day, no one can reach me. Has anyone else had this issue? Are there any solutions?