I apologize for the inconvenience you've experienced.

Kindly note that the Administrators have advised that the 'Acknowledge'/'Next' button is on a timer. It waits for 3 minutes to ensure that you've reviewed the content of the slide before it becomes available for you to select. You'll also need to be careful to stay on the course tab and not click away from the course or the timer will pause since you aren't able to view the content of the slide anymore.

Would you be able to try this and see if it resolves your issue?