I’ve seen the picture from the email notification I received. From what I can see it’s wired incorrectly. They need chopping off and replacing with the wires in the order shown in the link I provided above.
Don’t use electricians for network wiring.
What he’s done will checkout with a basic network tester. It would probably also work with very short cables.
There should be a pair connected to the centre two pins. Then another pair split so that goes either side of centre. Finally one pair to each side.