I have a Deco P9 with three units. The main is set in the living room and the other two in t the kitchen and bedroom. For a long time both my kitchen and bedroom units appear offline in the Deco app. And apparently both aren't working as the speeds I get in the bedroom are really low.

They used to work fine and the only thing that changed I the meantime was that I changed phone. I tried removing the kitchen unit from the app but now I can't add new ones as I always get the error message "can't add a Deco unit. Please try again later.".

Also, the main Deco unit shows no devices connected to it but there are several connected at the moment (and working). Actually I can't even reboot the main Deco as it throws an error. I also can't create a new network because it doesn't find a Deco unit. Nor can I reboot my network as it is, it just says "Failed"

This is amazingly frustrating and I'm seriously considering changing to another brand and trash this. 

Any help? Thanks in advance.