@Sunshine Also, wired connection and 2.4ghz wireless working perfectly.

@Sunshine Hi. Thanks for the suggestions. Changed the name and password for the 5ghz channel but no connection. Changed from auto channel selection to 36. Again, no connection. Message continues to...

We've been using the Archer MR600 V2 as an NBN WIFI router very successfully for the last 6 months. We normally connect through the 5ghz channel because it is much faster than the 2.4ghz alternative....