Monster Hunter Portable 3rd

[Kenjo]

Hey I'm having MH portable 3rd on my Android device. It is Working good (constant 30fps outside of the village) but the thing is inside the village the fps rate falls down to 18 and the sound Lags, which is kinda annoying. Me device runs with 3GB RAM which should be enough. Does anyone know what I can do? Maybe change some settings? Thanks in advance ^^
Edit: In quests it works fine, but when a hard fight starts, the sound begins to lag :/