Hi,
If you are setting up your config files, via vi editor, or UCI The system will be using the initial configuration until restart the service or restart the router at all.
You don`t have to restart all the services, you can use these commands to restart the specific service that you`re currently using.
/etc/init.d/sim_switch restart
/etc/init.d/network restart
/etc/init.d/modem restart
/etc/init.d/ping_reboot restart
By the way, if you want to restart all the services, according with this link, you have to use the luci_reload.
https://wiki.teltonika.lt/view/UCI_command_usage#UCI_set
I hope this can help you.