Media Encoder 2020 Pink Hazey Render Issue

Hi,

Updated 2019 to 2020 and noticed that any files above the HD frame size, you need to change the video rendering setting under pref/general to Mecury Playback Engine Software Only.

Anyone know why?  On 2019 I left it on the recomeneded option, which is the GPU Acceleraton (metal)option and Files above HD frame size rendered fine.  However in 2020, the recomended option gives it a pinkish haze on files above HD frame size, whether I'm down converting or keeping the frame size as source.

What's the difference between these options under pre/general/rendering ?  

Is the new vsn of ME compatible for making HEVC Rec2020 files? without shifting colour? (ACES colour management)

Thanks in advance

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