@Artur88Macau Yes please. Go with global or US

Please update the firmware of all your Deco M9 again using the tool. Run in compatibility mode under windows 10 Download the update tool from here :...

@Artur88Macau OK.. Let's try this. Create a Hotspot on your mobile with the same name as your wifi. Forget the WiFi password in the Xiaomi devices. Switch off all the decos and connect the xiaomi...

@Artur88Macau Try disabling the 5 Ghz network and see if the xiaomi devices connect to 2.4. Once you disable 5 Ghz band, reboot all the routers and Mi devices.

@JamesUK Glad it did. 👍

Disable Fast Roaming under the Advanced tab in the DECO APP