Well, if you tinkered around with one of those blue cloners, and it’s still working with the doors you originally set up to read it… then chances are the cloner set a password on the chip. Read these threads;
https://forum.dangerousthings.com/t/the-xem-cloner-project
https://forum.dangerousthings.com/t/quirks-of-the-t5577-cloning-tags-to-the-xem