Anders_ASUSSpent a couple hours and did all that, sim card works fine in my old phone... Still the same problem, except now I'm not receiving texts at all, regardless of where I am or what my reception is like. Hopefully switching to this new phone carrier solves the problem, if not then returning it is my only other option.
You could try and move your SIM from slot 1 to slot 2. If that doesn't do anything. Try the SIM in another phone and see if that phone can receive messages. Then you put the SIM back in your phone and see if it still behaves the same.
If there's no change, then you could try with backing up your SMS and then find the messenger app in settings -> apps & notifications ->see all apps -> in the top right three dots menu, press show system -> find and press messages (not messenger from FB) -> storage & memory -> clear storage. Not test receiving an sms again. If it works, then you can import all your backed up messages and test if you can receive again. If it never works, then back up everything and reset your device