Quiz (Question set) not working

I'm experience problems with the Quiz (Question set). The editor works fine, but when I try to display the quiz it shows a few seconds and then it disapears. It seems not to be a conflict with another plugin, since I've tried after deactivating all the others (except h5p), but Quiz Question set still didn't work. I'm running h5p on Wordpress 6.7 and the problem seems to appeared after the recent update of the Wordpress-plattform. I'm using h5p 15.0, but I've also tried h5p 16.0 on another website and Quiz (Question set) doesn't work there either. On the h5p 15.0 Quiz (Question set) version 1.20.11 is used, and on h5p 16.0 Quiz (Question set) 1.20.26. Do you know what the problem can be?