GMATClub CATs - Q51 but weird

So, yesterday I took a quant CAT here at Gmat club and I got a Q51 score. Needless to say, I was ecstatic, especially since I've heard that the math on these CATs is harder than the real deal.

However, my joy was short-lived. Throughout the test I had a feeling that the difficulty is much lower than previous tests i've taken here and I finished early, which rarely happens if at all. I looked at the analytics (see below) and lo and behold! I got as many as 12 questions in the 500-level range. Isn't it weird that I can have that many easy questions and still hit Q51? Why did the test keep giving me easy questions if I answered all of them correct? Is this Q51 at all indicative of what I might get on the real test?

Thank you so much for your thoughts!

SCORE 51 PERCENTILE 99 %

CORRECT 34 91.9%
INCORRECT 3 8.1%

CAT TIME
67 : 06 out of 75:00

RESULTS BY DIFFICULTY
Difficulty Number of questions % Correct
500-LV 12 100%
600-LV 8 100%
700-LV 17 82%