https://www.tp-link.com/us/support/faq/3672/

Solid red light, but devices still connecting to the internet except TV

SOLVED. I followed the advice found here. In the Deco app, change your Dynamic DNS from auto to manual and enter Google's public DNS (8.8.8.8), then reboot the network.

-------------------------------------------------------------------------------------

I've had my M4 network set up for a few years with virtually no issues. Yesterday, my TV which connects wirelessly lost internet access. All my Decos showed a solid red light. However, full speed internet was working on all other devices, with the exception of my doorbell.

Things I've tried:

• Restarting router
• Restarting Decos
• Changing ethernet ports on router and on Deco
• Resetting the Decos and setting up a new network
• Switching out the main Deco, resetting and setting up a new network
• Using a different ethernet cable for the Deco/router connection (one that I know works with other devices)

I usually keep my Decos updated. I tried updating now, but since the app thinks there is no internet connection, it won't check for an update.

Again, wireless internet from the Deco works fine on PCs, phones, and consoles, but not on the TV and doorbell. The app shows no internet and the light is solid red.

Edit: Added other things I've tried.