Books app won't open or delete documents on iPad

iPad (7th generation) with a number of mostly PDF documents. Updated to iOS 18. Within the past two weeks Books has stopped opening documents. Tapping on a document icon no longer opens the doc.he app opens without a problem. Same documents still open in Books on other devices tied to my iCloud account.

Tried a restart. Tried to delete individual downloads from the iPad, as well as all downloads. Books will not delete the downloads or open the docs.