@PBan 

I believe the issue is coming from a computer on your network that is querying the sites.

In any case, you could factory reset the router which will wipe any current configuration and load what is saved on the read-only memory.

@Tony 

Thanks, I will try with the factory reset. But it is not from any computer or phone connected to it as it happens when all devices are connected to my Verizon WiFi. I was wondering if there is any log or some trace available to see the source of the issue. But anyway, factory reset is the best option I believe.