issues with fail-over, cant ping 8.8.8.8 after the WAN is back to normal but can surf internet slow

Hi everyone!

I’m new to Mikrotik routerboard… okay let me describe my scenario and problem at the best i can.

there is 2 WAN [both PPPoE (different isp)] and 2 LAN… each LAN has been assigned to their on WAN such as:
LAN01 to WAN 01, and LAN02 to WAN02.

and I already make failover, load balance, and it works.
When the failover occurs and the assigned wan is up again, the LAN back to their assigned WAN… However, the end-user can’t ping 8.8.8.8 but can surf the internet and I notice it is take a time to load a page.

and it back to normal if the router rebooted or the physical cable at the end-user is unplugged and plug it again
I want to ensure this works automatically without reboot the router or need the end-user to do trouleshootig.

I already make a
mangle
route distance 1 for both WAN
Masquerade for both pppoe-out

it seems there is something to do with the NAT table, flush maybe… help me, please


thank you.