@HolyKrishna 

Thanks for the feedback.

I see the Deco M5 is still online from the cloud server via your TP-Link email ID and normally It should be working well.

Did your current issue start after the 1.6.0 firmware upgrade?

I have provided my email address in the private message and Could you please send me a screenshot of your IPV4 settings on the Deco APP>More>Advanced?

By the way, Do you have any wired laptops, and are they working fine?

Thank you very much.

Best regards.

  @dtaeza 

Hi, did all the devices fail to get internet service?

Please refer to this link to change the DNS server on the Deco to 8.8.8.8/8.8.4.4.

https://www.tp-link.com/en/support/faq/1855/

Please also make sure the ISP service and cable/fiber ONT are working properly and that only the main Deco is connected directly to ISP.

If possible, please unplug the main Deco and test the same port on the desktop to see whether there is internet service on the PC.

Thank you very much.

Best regards.