Same issue here, the first one works correctly and the second one is stucked on yellow. No fix?

@David_C this happened to my M5 Model just right now. It's still stuck on yellow, I've tried plugging it off, pressing the reset button, letting it rest for about 10-15mins and open it back up. but still, nothing happened. I hope this will get fixed right not.

@Carl 

sorry to open an old thread, but this happened too with my Deco AC1200. I lost power to the main deco. I was never able to connect to it again. After trying many things, I decided it was best to reset all 3 of my deco ac1200 devices and recreate my network. The other two devices reset just fine. They are flashing blue and I can find them on my available networks. This one however is still stuck on yellow. I tried all of the steps in this thread. Still no luck. Is there a fix for this? Ive only had the Deco devices for 5 days. I purchased them new from Sam's Club
 

Thanks

@CamJ 

We do have a process that aims to recover the Deco if it no longer responds or fails to reset properly (holding reset for 1 second).

Here is the FAQ: https://www.tp-link.com/us/support/faq/2958/

If that fails, it would be recommended to reach out to our support team.