[wstrayer]

I found that Saunders NPV does a better job than Fletch-Tite. It stays flexible and over time, the Fletch-tite does seem to loose its strength. NPV does take longer to set. It you are really in a rush, add a tiny drop of super glue to the ends of the fletch and set the clamp in the jig.
Regardless of the type, glues have a shelflife once you open the container. I the glue seems to be a bit thicker than you remember, then it is going bad and will not hold as well.