T90 pellets and that vol also includes the yeast.Did you use pellets, cones etc.? And how did you add them? My last brew was about 19L and I added 170g of pellets in a fine, mesh, hop cylinder. The hops expanded to about twice their volume but even if they expanded to fill the cylinder, there is not enough space in the cylinder for 3L of liquid. Let alone with the added hops taking up space.
Would a tightly packed mesh cylinder help squeeze the hops to recover some beer?