Strobing glitch using sobel effect

i’m working on a post processing effect that combines a sobel effect combined with the regular render. if i combine the sobel effect with a luminosity shader pass like in this example, or a ColorCorrectionShader it works fine, but if i remove both or combine the two, there’s a very bad strobing/flashing. any idea what causes that?

i made this test example here: https://jsfiddle.net/owenribbit/nfy9kthL/97/

if you remove the effectComposer.addPass(effectGrayScale); or add in the effectComposer.addPass(effectColorCorrect); you will see the strobing.

It seems I’m unable to reproduce with Chrome 90.0.4430.212 on Windows 10.

Do you mind sharing a video that shows the flashing on your device?

woops, i should have tested on more platforms before posting, but i do see the same thing on Chrome/Firefox/Safari on Mac as well as Chrome/Firefox/Edge on Windows.

the rate of flashing does appear different on my macbook pro screen vs samsung external monitor.

here’s a screen recording on chrome on mac
strobe effect warning

this recording is on my samsung monitor.