The Legend of Heroes: Trails of Cold Steel II [BLUS31597]

Been playing this on the newest version of the emulator. It works nicely, except for some dips in fps. But the black patches return after playing for maybe 10-15 minutes and does not dissipate until I restart the emulator.

Settings:
Sandybridge setup
LLMV Recompiler for PPU Decoder
ASMJIT Recompiler for SPU Decoder
OpenGL
Invalid Cache Every Frame and GPU Texture Scaling selected.