@Navea First check the IP address of the all Decos in the app. The satellite maybe is 192.168.71.xxx and main Deco maybe is 192.168.68.1. Then write the satellite address to your internet browser and your password. It is recommended to update when connected wired, but for me wifi worked fine via wifi. Upgrading the satellite took maybe max one minute and main Deco 2 minutes. I didn't even walk downstairs to update the satellite and I connected to the satellite via main Deco. Next time I think it will update in the app, if there is no beta installed manually before that.

  @Pelefin 

Thank you, this was the only way I could update them. Thanks again!

Any idea when the (US) official firmware version will be released? That's the region my models are and the notes say don't use firmware from other regions 

  @Navea Did you check your wireless backhaul setting in the app. After the update my wireless backhaul was working only in 2.4GHz (you can see it in the satellite deco information in the app), even I had disabled 2.4G backhaul in beta FW and I was using only 5+6G for the backhaul!! Further, tha app told me that 5G channel was 0 and 6GHz channel was also 0. The devices could connect to 5G/6G anyway. Further, channel selection was disabled in the app. There was no channel selection at all in the app! When I later noticed the issue I restarted both Decos. Now it works as it should. So, after updating all the Decos it's better to restart them all.

  @Kiwisam7 I understand that the FW download site forwards you automatically to the version that is meant for your country. As you propably know 2.4G channels in the US are 1-11, in EU 1-13 and in Japan 1-14. The same for 5G/6G channel width. For example in Europe you can only achieve 9300 Mbps theorethical speed, while in the US you can get 11.000 Mbps. If I remember correctly, there is 320 MHz 5G bandwith in the US and only 160 Mhz in Europe. Maybe the FW knows where you are, but still maybe not a good idea to install EU version in the US. The latest beta probably is almost the same and has all the features than the official FW will include.