I have had a deco m5 network setup for a few years and have not had any issues, however the last couple of days we have lost internet connectivity with all 3 nodes. 
 

I have rebooted the network 3 times and that has not fixed the connectivity. The app shows all three are connected and the nodes have green LEDs, so I'm unsure what the issue might be. 
 

Would appreciate any troubleshooting help.