Hi there, I have three DECO XE75 in my house. Two work perfectly. The third will connect to the network and is showing a green light, however whenever I plug a wifi cable into the port at the back to connect a device, the DECO fails - light turns yellow or red. 

Also, when it is showing a green light there are no devices connecting to it. I have updated to the latest version and have tried multiple devices and cables but nothing seems to fix the problem. Would you have any advice to assist? 

My ISP is Starlink and I have the main DECO connected to the Starlink device. All looks normal from that side, although there is a caution in the DECO app saying 'Abnormal WAN port speed. Please check your WAN port connection.'

Apart from the issue with one DECO, the system seems to be operating normally, but only having two DECOs available means I cannot connect all the devices I would like to. 
Many thanks.