I've been having this problem with my Decos where when a new device joins, I get 4 different notifications for that device joining. It's like something is duplicating, and it began happening when I switched the main Deco to a different Deco. 

As such it feels like something is wrong and needs fixing. How would I go about resetting the network to fix this, but without losing my previous Homecare/Homeshield data and without having to mess around with my router again in hub or modem mode please? Also are there any disadvantages in starting the network from scratch again? Thanks