Help to config carp with HA configuration

[wifi75]

Hello, I have two firwall configured in HA with carp on lan card and everything synchronizes perfectly.
One is named master and the other is backup, both use dynamic pppoe connection, and the wan ports are connected on a switch that is tagged to port 835.
when both are on they connect to the pppoe confiuration setnna and have 2 different public ip's.

Master's degree.
192168.1.40

Backups
192.168.1.30

Carp
192.168.1.1

the problem is that the dyndns is updated with the correct ip, it happens that if I try to turn off the master the ip on dyndns remains not updated and therefore I can't reach the firewall via dyndns.
While internal navigation always works!

maybe it's wrong to have carp on the lan?
the wan connection on the backup shouldn't always be active but only when the master shuts down.

How should I correctly configure carp to better handle the PPPOE connection?

this below is the pppoe connection used by my provider on vlan 835

this is carp configuration on master firewall