I found that the X end SLOW control was left on for ~15days. The output of the filter had grown to ~2e7.
This yielded the laser temperature pulled with the maximum output of the DAC.
This was the cause of the power reduction of the X end SHG; phase matching condition was changes as the wavelength of the IR was changed.
Once the SLOW output was reset, the green REFL was reduced from 4000cnt to 1800cnt.