@Fae Thank You for answer , for clarification :

I'm connected to ISP and getting DNS provided by him . In my case there are two DNS addresses :

re

89.171.34.2 and 89.171.34.3

On the PC all settings are provided by DHCP server , but at the very beginning i have used DNS provided by me as alternative, so : 8.8.8.8. with no success on this router.

Now I'm connected by my old ARCHER C7 and everything is work fine - as i mentioned in my description ISP provides me VLAN ID 30 for internet.

Both routers ( my old C7 and TL-ER7206 ) are connecting to WAN correctly , both are getting same WAN assignments. But just with PC connected to C7 i can get access to internet from its local address eg. 192.168.15.182.

In case TL-ER7206 i can ping external pages directly from router , through its internal tools. The TL-ER7206 is also indicating successful connection to  the cloud if enabled on router so there is already connection to the world. But there is no connection do the internet from the local PC with its local address 192.168.0.110 .

Modem has been restarted twice so even with default settings - except changes WAN configuration to handle VLAN ID 30 it still doesn't work.

Regarding pinging from local PC and your suggestion around DNS - it looks like PC can get proper address related to provided name , like when I'm trying do :

ping www.wp.pl

Im gettting info :

Ping from [ 212.77.98.9 ] with ....

But no replay from host, its looks like local requests are not properly transferred to the my public ip. I assumed that dynamically created routing table should work in this case without any issues - like it is in case of C7.

I'm planning check this router with with WAN without VLAN.