OMP Upgrade from 3.1.2-4 to 3.2.0: monograph cover thumbs error

migrating OMP form 3.1.2-4 to 3.2.0 now I’ve a problem with cover thumbs in the monographList and in the book page.

As I understand, upgrading to 3.2.0 covers and thumbnais move from files/ to public/

Now I see that the new thumbnails have a name like:
submission_265_265_coverImage__t.jpg ( with 2 underscores before the t.jpg )

but the img tag in the catalog and in the entry page points to a file with only ONE underscore


How can I solve? Do I have to rename the files?