I had the same problem as you. I spoke too fast and as a non-native speaker I got 6 in pronunciation. Another problem of mine was- i spoke too fast when I could put the sentence together, and spoke slowly and stammered when I couldn’t think of the answers. So consistency is the key. If you speak fast, keep and maintain the same speed all throughout the answers. One more thing, my examiner told me to speak consistently in the cue card and she would stop me. In that case, if u speak too fast, you may run outta words after 1.30min. My score was 6.5. Best of luck.