The easiest way to solve this issue is to insert the sim into the device, get a pin and hold the RST button in for 10 seconds. Whether you're a beginner or just need a quick reference, this article is written to. Connectivity issues are typically caused by a variety of reasons when traveling abroad. The phone displays only the carrier name, such as “CHN-UNICOM,” but does not display 4G, LTE, or 5G. If your sim still doesn't work and it shows in Slot #2, verify your IMEI number is valid. However the GPON device may be unable (or unwilling!) to respond to anything outside it's own subnet. In which case you'd need to add a VIP on the pfSense WAN in the 192. X subnet and an outbound NAT rule to translate your traffic to it.