Can't write xEM tag any more


I’ve had an xEM tag in my left hand for a couple of years now and I’ve cloned cards to it several times using the cloner I got on the Dangerous Things store. It worked like a dream until the other day when it failed to write. I even got that chinese multi-frequency reader/writer on amazon to see if the cloner was to blame. no dice. The tag is still readable, but it’s like the read-only bit got flipped or something. Any thoughts?