What type of issue is this?

Incorrect support data (example: BrowserX says "86" but support was added in "40")

What information was incorrect, unhelpful, or incomplete?

It's weird a WebView would provide different support than Safari proper:

What browsers does this problem apply to, if applicable?

Safari

What did you expect to see?

Maybe notes that support needs to be configured (as the native/consumer side needs to handle extra things if it declares support) — but not difference in actual platform feature support?

Did you test this? If so, how?

iPad mini 26.2 running Chrome iOS (a WKWebView consumer), using this: https://jsfiddle.net/ecy9zv8s

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

I'm having trouble finding any documentation to corroborate the current Safari vs. WebView difference in bcd data for this — hence why I'm raising this. Might have just missed something obvious, though.

Do you have anything more you want to share?

No response

MDN URL

https://developer.mozilla.org/en-US/docs/Web/API/Fullscreen_API

MDN metadata