@Scoredo 

Hello, sorry to hear that you encounter an unstable issue with the Deco P9.

Please help confirm some details and we will try to figure it out:
1. May I have your detailed network topology/layout? What’s the operation mode of the Deco? On the Deco APP, please tap “More “on the bottom right corner then go to “Advanced”, where you will see the working mode.
2. Can you please confirm how all the Deco units are connected, via wireless or PLC? You may confirm it as below:
On the Deco app, click on the Internet icon, then click on one of the satellite Deco, and you will see the satellite Deco’s signal source. If there is a Wi-Fi icon on the signal source, it means the satellite Deco is using the Wi-Fi backhaul. If there is a Powerline icon, it means the satellite Deco is using PLC backhaul. Please ensure that both the two Deco P9 units are plugged into the wall socket directly but not to power extensions.
3. When the RE Deco loses the connection, how about the LEDs on the Deco units, are they all blinking red or solid green?
4. How often does the disconnection issue happen and how do you make it back to work?

5. Which beta firmware were you using before? Does that firmware have no improvement at all?

Good days.