H5P Flashcards issues after WP update to 5.2.2

1. Detailed steps to reproduce the bug (exactly how and when did it happen)
   The issues happened when I updated WordPress...and also when I update the H5P plugin itself.
   
   
2. Platform and version number. E.g. Drupal, Wordpress, Moodle.
   WordPress version 5.2.2
   
   
3. Mobile or Desktop
   Both
   
   
4. Browser: Chrome, Firefox, Safari etc
   With only the plugin update, it does not work in any browsers. With the entire WP update (but reverted back to 1.11.3) it still works in Firefox, but getting loads of errors in other browsers. I have attached the console errors I get in Chrome. 
   
   
5. H5P plugin version
   For now I have reverted the plugin version back to 1.11.3. Updating does not solve the issue cause by the WP update. So I figured let's focus on getting it to run on an updated version of WP first. 
   
   
6. H5P content type and version (if a content type was used), and a sample URL or attached H5P.
   Flashcards. www.ownyourchange.dk...however the site has login restrictions...I don't want to provide user and password for everyone in this forum. But feel free to contact me directly for this if necessary at [email protected]
   
   
7. Any browser console errors
   Loads...see attachment.
   
   
8. Any PHP errors
   No
   
   
9. Screenshots if it's a visual problem
   Screendump attached
   
   
10. Any recent changes to the environment (new plugins/modules, updates, configuration changes etc.)
    At the moment only a WP update.
    
    
11. Any recent changes to the browser you're using (new extensions, updates etc.)
    No
    
    
12. Additionally, when I click the Edit button of my already created Flashcard element in the WP admin module, it just keeps loading...and loading...forever. And a lot of console errors come out. See attachment for this as well. 

I hope someone can help. Thank you in advance ;)