we use Moodle 3.9. We observe the following situations while doing quiz:
-Sometimes students cannot see the Next button to confirm the current choice and to go to the next question. When refreshing the page, the Button reappears.
-Sometimes, in the last question of the quiz, there is no button Finish attempt. So they have to wait till the expiration of the quiz (it is a timing quiz) in order to submit the result (forced by the system).
The issue happens quite often but it does not happen to our staff, so I cannot provide any further debug information. Do you have any hints to track / solve this problem?