Having trouble with CFA's assessment questions

Is anyone out there having problems with the questions from the CFA Level 1 assessments (from the website)? I am used to score between 75% to 85% in the CFAI EOCs, 75% in the Schweser EOCs, and around 80% in the Qbank; however, there is a huge standard deviation regarding my scores when completing the CFA assessments (between 55% to 70% in general). Shoul I be worried? I find those questions very tricky, and more difficult than the ones I am used to do.