I have a similar issue. For developers who have implemented deep links, maybe from firebase or branch.io, the dynamic links have 301 or 302 redirects to the original links. Such dynamic links are not opening in the in-app web browser. It throws net::ERR_UNKNOWN_URL_SCHEME.
And yes as mentioned by @mister_pope, this maybe can be solved by setting a client in the webview and pass the url to an intent.
@Piotr, can we get a fix for this?