I'm finding my LG G7 ThinQ (LM-G710VM) is frequently getting stuck in 1X data mode since System Update 7 (the Android 9 update). This appears to occur when I've lost service and re-entered an area of service (4G LTE service does not restore).
LTE data service is restored by restarting the phone or cycling airplane mode.
Software updates should enhance the device. Sorry to hear that this is not happening with your latest update. We can help here. Do you receive any error message on the device prior to the issue happening or when losing service? Does this issue happen everywhere you go or in one location?