@Joseph-TP 

G'day Joseph.

Well I'll be blowed.

I tried one of your earlier suggestions to someone else about changing the DNS servers used and that seems to have stopped my router misbehaving. Stone. Dead!

My Archer AX11000 has been rock solid (touch wood) since so I'm a happy chappy (wife is also now happy! Happy wife, happ life! Yah).

Fingers crossed it keeps working OK.

Many thanks for your help. Have a good one!

Joseph-TP wrote

Hello @Davo_esq ,

A hard reset will not change the firmware version. If a hard reset doesn't help, we'll escalate your case to an engineer.
Thank you for your understanding.