Remove the APN. let it auto-detect.
Also, here are the steps from the LTE activation guide:
ACCESSING CELLULAR SETTINGS
1. Ensure SIM card is inserted in the appropriate slot of modem or router
2. Power up the WiFiRanger system with embedded LTE modem(s)
3. Connect over ethernet or wirelessly to the WiFiRanger’s network SSID
(Instructions for this can be found here: https://wifiranger.com/wp-content/uploads/2020/02/wifiranger_quickstart_sky_lostdocs_rev8.pdf )
4. Access Control Panel of the WiFiRanger and select the “Setup” tab
5. Expand modem settings by clicking the appropriate gear icon: a) Standalone WiFiRanger (indoor or outdoor unit): (I) Click “Cellular” gear icon b) Pack WiFiRangers (indoor and outdoor units): (I) Click “Cellular” gear icon to access indoor unit modem (II) Click “WFRControl” gear icon to access the outdoor unit modem
6. View SIM & IMEI numbers after expanding the modem settings
