What does "Unknown Wait" on a hold mean?
"Unknown Wait" for a hold means that the title has expired, but the library hasn't removed it from their Libby catalog. Some libraries use holds on expired titles to help decide if they should purchase more copies.
If the library purchases more copies and you're on hold, you'll start moving up the wait list like normal.
If you have questions about a specific expired title, reach out to your library for more help.