@David-TP Thank you very much for your reply. I have managed to resolve the issue. It appears that the deco S4 was confused because there where two different providers so I had to create a policy...

Hi , I have a SYNOLOGY T2600ac Router WIth Two Broadband different providers lines coming in to it set to 50/50 Balancing +Failover. I have 3 Deco S4s with the Main Deco pluged in to my router and...