I bought 3 scroll effects (Resource +20%) and stacked them on my sword, ring, and plug. Shortly after that I got 10 rough diamonds beating Astaroth at Lavalanch, but now I only get 6 rough diamonds from him and only 6 cannonballs from beating the Dark Knights at Solitude Peak aswell. Seems like the resource increase only applied to 1 Duel and doesn't work anymore.