I bought my Samsung s9 few months ago having problem with sending text messages at calling.
When I'm sending text messages it doesn't always go thru many times failed sending.
And when I am calling it takes almost a minute before I hear the ring.
I went to the mobile shop where I bought it and they replace the SIM card. But it's still the same problem. I'm with Fido network I don't have this kind of problem with my S7.
it may sound dumb, but I would suggest enabling auto restart at least once a week, also maybe clearing your devices cache partition. this could help, maybe someone else that may know more then me about this issue will give more tips. 🙂
