Flycast graphic error & core option question

Hi, i use flycast core to play a Dreamcast japan pro-wrestling game, but meet some graphic error as following screenshot. The character models are all constantly glitch & distortion (different distortion result every frame). Are there any core option combination can resolve this? or any way to fix it?

Another question, the docs page of retroarch mentioned there is a core option named “CPU Mode”. ( But i can’t find it in my Retroatch flycast core option. is it still availible?