@woozle Not a silly question, you're bl**dy right! It looks as though the guy who installed the fibre modem got the power adapters mixed up. Thank you so much for your help!

I've changed FTTP ISP from one that will work directly with my AX72 router to one that won't. I naively thought that I could just plug the router from the new ISP (Sky) into the AX72, log in, change...