We're experiencing the exact issue that's in this support article:
The black frame or bars that you see, appear in the preview of the video only. Important: When you play the YouTube videos, you will not see these black bars, provided that you are using the appropriate aspect ratio. We have thoroughly investigated this issue and found that the root cause is on YouTube's end and affects all embedded YouTube videos, regardless of where the video has been embedded.
Can someone explain what this means exactly?
We've never seen youtube embeds on mobile being displayed like this. Are we missing something? We're on the verge of moving back to squarespace because of this.