Histogram issue?

Recently I noticed the histogram in PS4 displaying color channels instead of luminosity. And all three RGB colors seem to spike off the top of the window.
Is there a way to only display the luminosity histogram curve??

Also, how often would be considered normal to have to re-set preferences?

Thanks,

Barry

Select Expanded View in the histogram flyout menu. Near top of the expanded view panel select (Channel:) Luminosity or RGB. That channel selection will persist on return to Compact View.

Ah!

Thanks!!

I find that an annoyance also. Is there a way to set the luminosity view as the default?