@JimNZ Go through this thread to see the details for this issue.

@omeletterice 1.Yes, it will work if you set the Deco in AP mode. 2.The main Deco should be wired to the main router - see the details here.

@Tammmy You probably using this scenario (Case 2) considering configured static routes for NTP update. The problem is that Archer C5 v4 has a customized FW for ISPs and you can't update it to fix...

@JohnWMcC Yes, that's the correct approach.

@HeshamEwida Probably some minor HW changes.

@Novascape Here's a guide on how to optimize your wireless speed and range. For better wireless speed it is recommended to use your 5GHz band.