For this type of behavior I would recommend submitting a case in your secret customer group where the next available support engineer can assist with further investigations into your instance. When you open the case, if you could please include the following information it should assist in the process:
1. A link to one of the blogs where this behavior is occurring
2. Does this behavior occur with all embedded videos or does it appear to be related to a specific file?
3. Is this behavior limited to embedded video content, or are you seeing the same behavior when using the create >> video option?