Hey, you would not believe that if I had no proof ;-) ... but the true cause of the "yes cards" was some kind of glitch on side of visa/mastercard AND the banks

Hey, you would not believe that if I had no proof ;-) ... but the true cause of the "yes cards" was some kind of glitch on side of visa/mastercard AND the banks. So at that time some banks had not even issued chip cards to their customers. If you "cloned"/transformed the data from the magstripe to the chip and tweaked a few bits ... well, that confused the system and defaulted to "yes" due visa/mastercards setup/fallback. Naturally, this problem has sloved itself by now.