Theme App Extension: Doesn't render block settings properly

[htanipog]

I have the schema defined in the locale where it works for text field, but not in 'select' label

If I "add" the block, "Save" and "Exit", revisit the same, I don't see the error message. 

Have been exchanging emails with shopify support. They claim it is our app issue if we see the same behaviour in 3rd party themes. Idk how! There is no API call involved here. Once we do `npm run deploy` everything is out of our control. And if the rendering isn't proper while the block is added, but works when we save, exit and come back, I'm quite unsure how to fix this at our end. Any thoughts?