A RB with 2 PPPoE xDSL WANs, each WAN obtains his unique IP address, plus a IP for its default gateway that’s equal for both. A “mark routing” Mangle Action is used to mark the outgoing packets thru WAN1 or WAN2 after a PCC calculation to create the load balancing. But no matter the marking you do, because both WANs has the same IP address for its default gateway, the routing logic ends using only one of the WANs, indeed nulling the load balancing. How to fix this situation?
In case of PPPoE (as well as any other flavors of PPP) you can use interface name instead of IP address as a gateway in the routing table.
I know that and I do this way, i.e., I use the interface name in the gateway routing table. But it doesn’t works because, at the end, that interface name is translated to the gateway IP address that’s what the routing logic consider at last instance. So the routing marking has no practical effect when different interfaces with equal gateway address is used.