That's correct, Pascal.
Assume the first part is based on 89 questions (as it was in my case); once you answer the 89th question, the system prompts you that you completed the first part pf the exam, and invites you to review your questions before the submission. In fact, you have the option to revise them all, or just focus on the marked questions (I chose the second option). As soon as you finish reviewing the questions, you submit them (the system will ask you twice for confirmation, warning that you will not be able to access them again), and the timer pauses, (say) at 135 minutes left.
Now you have the option to take a break or move on to the second part. Once the second part begins, it will start with question #90 and 135 mins for you to complete the second part.
Hope this clarifies what I meant in my previous message.
Gabriella