Mikrotik Script to reconnect the pppoe that get the NAT IP. Some ISP provide both public and NAT IP to subscriber. Create a ppp profile and put this script in On Up section. Update the wanInterface according to yours.

reconnectnatip.src

:global reconnectCount;
:local wanInterface "pppoe-out1";

:while ( $"local-address" in 100.64.0.0/10 ) do={ 
    :log warning ("$wanInterface: Got Private IP ".$"local-address"." Reconnecting the interface...");
    /interface pppoe-client disable $wanInterface;
    :delay 10s;
    /interface pppoe-client enable $wanInterface;
};
:log info ("$wanInterface: Got IP ".$"local-address");