Bug with multiplayer sessions

I'm playing with my 3 friends and we're doing challenges together in Co-Op mode.

Every time everything IS completed, there still is the co-op challenge: All players complete the Line (*/*), which doesn't count sometimes, even though everyone did the challenge and nothings missing. All of us also tried doing everything in a sequence, but that doesn't work as well (same thing with the All players do tricks at the spot(*/*) challenge).

Anyone else experiencing these problems?