I thought it was an miscalculating, but recently I checked and happened. I had 5 favor only, but I made the "Win 7 Games" and, at the same time, reached Guan Yu to Matery Level 6. Instead on give me 320 Favor (270 from Quest + 40 for Mastery + 10 for winning the match), it give me 280 (Quest + Win). It already happened few times with Guan Yu.
Please, fix it n.n