Another update: I firmly believe this issue rests on Emby and not mycroft after deciding to review the logs. I’ve created a topic over there, and they informed me that this a bug with Emby. I’ll close the issue here, as this is not a bug with mycroft.
Final update: it appears Emby has been updated somewhat recently, and now everything works fine. I don’t see a way to close the issue, so if anyone has issues, please create a new thread.