Hey Philipp! Great hearing from you again. Hope you’re enjoying the new update so far. So I’ve checked into this, and it’s an unfortunate bug going back to the early days of X where we saved those meta keys with HTML encoded into entities. There’s not a clean way for me to reverse this without breaking existing sites 
but for the next patch I’ve added a new parameter in dynamic content that should help make it possible for cases like this.
{{dc:post:meta key="_x_video_embed" decode="true"}}
Once we get the next update pushed up, try it with that decode attribute.
Thank you, Alex! i missed you too 
You’re welcome!