Yes, it seems like using %20 in the query parameter works…
However, this is incorrect encoding for application/x-www-form-urlencoded data and query parameters, so I hope you will look into fixing this, since it requires additional implementation client-side to produce a custom query string…
Good stackoverflow thread on this topic (for some reason the forum doesn’t want me to post a link…):
Do you still have this problem if you swap the + separating the scopes with either an actual space or %20? This may be a mistake in the docs saying that you can use the +.