We have two chipped cats, both have been able to enter through the flap without any problems. Without warning, the flap no longer let either of them in, and after the reset only cat 1 can be read in, cat 2 is not saved. Now I have bought an identical model and the problem is exactly the opposite; this flap only recognises cat 2, cat 1 is not saved when it is read in. What can I do? I have already tried resetting both several times.