Absolutely. At least for French and Irish, the listenings are insanely difficult. I drop from H2/H3s in real listenings to H5s in mock listenings (in Irish I dropped from 100% in a real listening to 60% in a mock one). It's unacceptable how difficult they are compared to the real listenings and I reckon that you'd jump at least two if not three grades automatically from a mock to a real listening. It's really just listeninga that have this major problem, comprehensions are also more difficult, but only because of weirdly phrased, ambiguous questions that try to catch you out. Written pieces are the same.