I think earlier i did some checked and unchecked on port binding and apply at wan config like first on port 2 and then port 1 and then both and also when I added virtual server port 80 and saved it without enabling it, those previous steps merged together somehow which knocked out internet on lan, i did removed all the port forwarding rules and delete the whole wan config and tried with new one and also did 3 resets but somewhere it saved in cache or stuck to firmware image. (its not possible but don't know what was the reason).
Thanks. It's working nd able to ping internet on lan devices by these steps.
step 0. Delete all wan configuration from onu.
step 1. new wan config Bridge mode | ipv4 | vlan xxx | untick disable lan dhcp,(WAN CONFIG)
step 2. connected with ppoe form pc using onu bridge mode
step 3. to remove the virtual server cache while in bridge mode, Application>>advance NAT>>Virtual Server>>add | 80 tcp/udp | 192.168.43.37 | enable. and then delete the whole port 80 config rule.
step 4. disconnect ppoe form pc while on bridge mode
step 5. Delete the bridge wan config from onu step 1 (from onu)
step 6. then make a new wan configuration ppoe on onu as usual with user and pass and vlan stuff. but not checked "Disable LAN DHCP" and selected binding port 1 and port 2.
then internet is available on all the lan devices.
i did 3 onu resets which does not delete the virtual server cache, i think after adding and removing a new port (80 tcp/udp) forwarding rule while bridged to pc reset the unknown cache .
btw i used virtual server aka port forwarding before no issue faced,
