I’ve got the same issue with the Stroop test. I think what it does is it display all of the stimuli at once very briefly under the main stimuli, when each trial is launched. What I did as temporary solution was to insert a lot of blank space under the stimuli, for each of the questions (Init, Q1…. Exit). So this error still happens, now it is displayed much lower on the page…essentially you just get a much longer page.
You need however to insert the same number of blank lines and also make sure they are enough blank spaces for larger screen sizes too!
The downside is the possibility to accidentally scroll down but since the fingers of the person would theoretically be on the keyboard, not the trackpad, this would be highly, highly unlikely.