The blue film base must be anti-halation backing that was not removed in normal processing. Soak the film in a dilute solution of sodium sulfite (1 teaspoonfull per liter of water) for about ten minutes and the blue base should go away.
Stain should not add extra printing time with silver papers unless the film was over-exposed, or developed much to much, or the film is outdated and has a lot of B+F.
The blue base is not leftover anti-halation dye. This film, in medium format, has a blue tinted base. I've seen it myself and it is so described in the manufacturer's documentation.