I think that H5P is in conflict with jquery (see attached file). We had a functioning H5P installation. Then we incorporated LearnDash and MemberPress, and when we copied the new installation over the old one, there are two problems:
1. some, but not all, quiz exercises fail to load, and cannot even be edited. They display a "unabletocopy" error.
2. all dictation exercises are no longer playing the embedded sound files.