OK mobile removed
I don't believe its a power issue as i never experienced that before with the previous version.
Hmm. wonder if the router is failing. I might pull it apart.
current status.
5Ghz enabled. everything works.
2.4Ghz enabled, WAN & WAN6 drop. because I have a wanb setup in MWAN3 the internet connection continues.
I can live with this for now.
Thankyou for your help it is most appreciated.
In short, check device MAC addresses.
Got to the bottom of my WAN port & WIFI problem.
The end result was both devices, the WAN assigned port and the WIFI device, had the same MAC address.
Resolution - change WAN port MAC address. So both are now different. Now everything works as it should.
That is the great fun of using ancient kernel, enjoy.