Dektol 1:3 for 60 seconds is your normal development time? This is where you are arriving at your ISO of 25?

Dektol 1:2 for 2 minutes seems like normal print paper development time for me in my own darkroom work. The Sprint paper developer I am using is nearly identical to Dektol.

Maybe that's where the difference is coming in. I'm going to scan these negatives right now...