My Oppo R9 has stopped sending and receiving SMS messages. I have done all the troubleshooting steps in the Optus site and nothing helps. When I put my SIM in another phone it worked fine. But I want to use my Oppo phone as normal. Any ideas?
Could be your APN settings.
In settings on your phone click on SIM & network>SIM yes optus>access point name>hamburger top left corner>reset APN
Further information on APN settings is available here → Our Mobile Phone APNs & Technical Settings. Let us know if this works for you.