No embedded content displayed
Embedding h5p content doesn't work in browsers which have 3rd party cookies blocked (it's a native browser setting, not an addon, tested in Chrome and FF). The console displays error: "h5p-x-api-event.js?o721st:191 Uncaught SecurityError: Failed to read the 'localStorage' property from 'Window': Access is denied for this document." The script is trying to access localStorage, which results in error. Maybe wrap it in try/catch or use cookies?