The activity (Column) doesn't display anything

Hi,

• Detailed steps to reproduce the bug (exactly how and when did it happen): I have chosen an activity (Column) with several tasks. Several students from different courses have complained that they don't see any content, and therefore can't complete the assigned task. When I check the activity in their course, I can see the content. And when I switch to 'student' mode to test it, I also see. I have also signed up for these courses using a different account. I can aslo see the content. Then, I asked 2 different student from different courses to give me their login and password, so that I can check myself. So I see nothing indeed.

  How I tried to solve the problem:

  I used the activity (version 1) and duplicated it (version 2). Both versions did not display the content (the tasks). Since nothing had changed, I imported same activity from the original course (version 3). The thing is that version 1 was also imported from the original course.  

  The problem is that some students might fail to complete the assigned homework because of this problem. And I have no idea how to fix the problem. But the strangest/funniest thing is that some students had no problem with version 1, so I can't delete it because the their grades will disappear. I think that creating the acitivity and duplicating it just to make sure that one of the versions will work does not sound as a good solution. 

• Platform and version number. Moodle (3.5.12)  
• Mobile or Desktop: Desktop
• Browser: Chrome, Safari
• H5P plugin version: 1.20.2 
• H5P content type and version (if a content type was used), and a sample URL or attached H5P.
• Any browser console errors: no
• Any PHP errors: no 
• Screenshots if it's a visual problem: attached along with h5p file
• Any recent changes to the environment (new plugins/modules, updates, configuration changes etc.): no 
• Any recent changes to the browser you're using (new extensions, updates etc.): no