Challenges disappearing?

I keep getting notified that clans have challenged me, but the challenges don't show up in the last as they've done for two years...

Has something been changed with regard to the challenges? something I'm not aware off. Its startint to tick me off. This is like the 4th consecutive challenge I've been notified of, but when I check the list, no challenge present.

Now, had it been one or two, i'd settle with "he prolly withdrew the challenge" but thats not the case.

Anyone mind telling me whats up?