Cute little fella.....
I am out of suggestions...looks like you have tried or thought about everything...
Just a shot in the dark...he may be just playing..bored...you could divert his chewing to something else. They have to chew.....teeth and gums feel better when they do..
Thanks so much, again! He’s a bit of a devil. He knows he’s always chased from those cords..lol. He has several chew toys and other items. He just likes those cords and the wires. The modem blinks, so I turned it to face the wall and that “helped.” (He only goes to those cords and wires when I’m not looking!)