Card blocked but only at KFC.

I use my Capitec card regularly at KFC. On Tuesday morning I wanted to pay at KFC for my order with my card and it was declined with the error message saying that my card was blocked.

Later the day I went to the Capitec branch and they checked it but couldn't find any problems. So they reset my card and pin for in case. I was told to try again. I went to Checkers and used the card without any problems whatsoever. This morning I went to KFC again and again my transaction was declined, again showing "card blocked". I did use the card at other places after this and everywhere it is working as normal.

What would be the problem that it only shows "card blocked" at KFC?

So now I rather buy at Chicken Licken where my card works and isn't blocked.