My filter setup is similar.
Powders on 25 micron mesh gasket
Double 8 micron paper
Double 2.5 micron paper
Double 2.5 micron paper
Usually the 8 micron paper catches a tiny amount of fines, but the 2.5s always come out clean.
I’ve been seeing big yield losses, no matter the material age. Losses from 30% on freshly dried, to 70% on year+ old. I use 50g per lb of silica 60, might try reducing the amount or dropping it for a test run.