I have a network of 5 Deco P9's. 
 

I'm running a 5G CPE PRO Router with DHCP disabled (bridge mode not available) connected directly to the main P9 with an Ethernet cable. 

The deco system is set up as a Router with a fixed IPv4 address. 
 

The 4 satellite P9's are connected to the main deco via WiFi & PLC, sometimes they recalibrate to daisy chain connection to the main deco. 
 

I've never had any problems with the main deco, the speeds are always similar to being connected directly to the 5G router. I've disabled WiFi on the 5G router to reduce interference. 
 

Predominantly the mesh system works really well but it's incredibly unstable, it'll drop out for no reason on the satellite decos, the WiFi itself doesn't drop out, only the internet connection. 
 

It was having problems with an old sky box and printer but I created a 2.4Ghz guest network to isolate the 2.4 network from the 5 for them and it seems to be working fine now apart from the random internet drop outs. 
 

The system connects an IP camera between two decos to add it to a network of other IP cameras which works fine normally but sometimes cuts out for no apparent reason. 
 

I've had problems with powerline adaptors in the past with restricted speeds since my power is relatively messy, the decos say in the app they are connected with PLC & WiFi. If the power line for whatever reason drops out will it not connect on the WiFi backhaul automatically and quickly instead or will it trigger a drop out as it tries to figure out it's broken? 
 

Is there a way to disable the PLC and test if it is more stable? I appreciate there are other Decos who solely rely on WiFi but if possible I'd rather not completely rebuild my network. 
 

It seems others have run into this problem with instability and drop outs over the years and are often suggested a beta firmware update, my decos are all running 1.1.3 Build 20201228 Rel. 55057.

My CPU load seems to be at 100% when there isn't many devices connected, not sure if that's a problem or the system reporting it wrong. 

Others have also suggested changing to Access Point mode instead of router, should this really make a difference if the main routers DCHP server is disabled and the decos is set up correctly? 
 

Any advice would be greatly appreciated, thanks.