Answer
This is most likely related to the QIS view's own naming convention (which can include a double $$ sequence) being misinterpreted by the Lobby engine as an in-view parameter placeholder, rather than a hard restriction against QIS views generally. A practical workaround: create a plain IAL (Information Access Layer) view that simply wraps the QIS view, and point the Lobby data source at that IAL view instead of directly at the QIS view — this has resolved the 'Page Parameter is missing' error without needing to abandon the underlying QIS-based query.