GMAT Official Practice Test 6 score confusion

Hi All,

I recently appeared for the GMAT Official Practice Test 6. Have a major confusion in Verbal section, described below:

GMAT Official Practice Test 5: Scored a V34 by getting 22/36 correct
GMAT Official Practice Test 6: Scored a V21 by getting 23/36 correct

Based on my analysis, below are the possible reasons:

1) I think the level dipped when I got 2 incorrect easy CR questions (< 600 level) in a row in the first 5 questions
2) I missed last 3 questions as I ran out of time (they were also < 650 level)

To add, I appeared for these mocks (in order) on consecutive days.

Can anyone comment and explain such a major drop in score? What should be the strategy going forward?

Thanks in advance.