Webapp assigns numbers incrementing by 2

Hi all,

URL of experiment:
Oldness: https://moryscarter.com/vespr/pavlovia.php?folder=EDeKorte&experiment=oldnesstry2/
Material: https://moryscarter.com/vespr/pavlovia.php?folder=EDeKorte&experiment=materialtry/

Description of the problem:
I am using the moryscarter webapp to assign incrementing participant numbers for my counterbalancing to work (participants with an even number are assigned condition 1 first, participants with an odd number are assigned condition 2 first. The moryscarter app runs very smoothly with my experiment, but I have an issue with the incrementation. As in the post below, the number seems to be incrementing by 2 (I went from 16 to 18 for Oldness and 17 to 19 for Material).

The incrementation will affect my counterbalancing, so I am just curious what the issue might be.

Thanks in advance.

Kind regards,

Ellen