DDNS settings change upgrading from legacy GUI firmware

When we upgrade our RUT240 routers from 1.14.7 to to the current 7.06.3 (or any 7.XX) firmware, Our ddns changes from “Network - Mobile (PPP)” in the legacy firmware to “Network - Wan” in the new firmware. This causes us to lose access to the devices until we have physical access to the router and we can then change the Network to “MOB1S1A1.”

What can we do to get the unit to take this setting during the upgrade?