MacOS import pdf to Books failed - bad filename?

Upgraded my device from 2020 Intel Macbook Pro to 2025 M4 Macbook Air.

Upon restoring from Time Machine, I was unable to add new pdf files to Books.

When uploading copies of my books individually, importing new pdfs is met with "Failed" at the bottom of the book list. This never happened with the old device. Resetting the online access and identifier in Books settings did not work. Neither did restarting.

However, I noticed that some books have file names that cause issues. For example, if my library contained any pdfs with file names beginning with "[" it would fail. Renaming the file by removing these special characters allowed successful import.

Will continue to experiment with this. Is this something particular to M chip macbooks?