I don't have that issue, but I'd try keyboard navigation to see if it may be a mouse issue.
Click on a cell in the book list, then use arrow/tab keys until the column is selected. Press F2. Then use Y, N, and U keys to set them as Yes, No, and Undefined. (The last one was added in a relatively recent update—I'm the one who requested it—so it may not be available if you're using an older version.)
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