Key not found

Hi all, recently bought a 2016 Fabia 1.2tsi with 1 key and it's the push button start, had 2 mobile locksmiths out and both have the same problem, they can cut and programme the keys so it locks and unlocks and will start the car but the new key they cut will only start the car if held right up to the button and then you get the dreaded "key not found" warning and noise,the original key works fine so I can't see that it's a car fault and I can put up with holding the spare key up to the switch as I'm not going to pay £360 for a key from Skoda and then another £75 to code it for them to find the same thing but I'd like to know can I disable the the warning noise???