Skate-o-Ween completion bug

I noticed that after having completed all the skate-o-ween challenges in co-op i have only gotten 10 of the 12 goals needed to complete the skate-o-ween task, but there are no other challenges to get goals in and i have all the goals in the existing three challenges including the co-op goals. not sure whats wrong as all of my friends received it but mine decided to bug out.