@HuibC 

Hi, Thank you very much for the feedback.

Now it keeps blinking blue, even after resetting and disconnecting the power supply. The app also doesn't recognize this DECO unit. On the other hand, my phone sees this unit as WiFI access, and we can access the internet using it.

- Do you mean, even though this satellite is flashing blue and Deco APP doesn't recognize this device, devices can connect to this Deco and get internet access?

One of my other DECO X60 units is working, but I can't update the firmware to the newest version.

-Since there are different hardware versions of Deco X60, can you help me check if all your Deco X60 units are V3?(You can check it on the bottom product label)

(It would be very helpful if you can note down the hardware version and its current firmware version, Thank you in advance.)

Wait for your reply and best regards.