Text Box Entry doesn't work correct when repeating the Quiz

Dear Adobe Captivate Forum User, I'm using Adobe Captivate 8. I've created a slide with eighteen TEB's on one slide. User have to confirm with "Enter". If User  tried it the first time, it works excellent. On the Quiz Result Slide I gave to User the possibility to try it again. After a few field's the system hang. Sometimes it maybe that it happens after 7 fields, sometimes it happens after 9 fields. It's always different. I made this experience while testing it with an excecutable file. I tried it on different computers. In the Quiz Result Slide, by activating the slide, I setted up all variables with 0. There are no specific options in every field. Would you mind telling me your experience or sending me a feedback? Thank you very much for your efforts. Kind regards from Leobersdorf in Austria.