1. On the web, create a post and add a video block. (I added a video already uploaded to the site's media library.)
2. Save the draft.
3. In the app, open the draft post.

Expected: The video blocks will load (or at least the video block with no caption will load).
Actual: The error “Problem displaying block” appears instead for both blocks.

Saving the post in the app and trying to open it again on the web results in an error on that end: “This block contains unexpected or invalid content.”

I also confirmed that the same “Problem displaying block” error occurs if I add a video in the app, open the draft on the web and save it there, and then reopen the video in the app. There seems to be an issue between how Gutenberg web saves the video block markup and how Gutenberg mobile expects it to be.

Tested on iPhone XS, iOS 12.3.1, WPiOS 12.7.0.20190617