I had the same problem with my Tab S7+ & reported it to Samsung via the get help section on the Samsung Members app. while I was waiting for a response I solved the problem for myself. I use the screen enhancing option in the accessibility option in settings. when you do this the blue light filter should be disabled. at night I keep the display at low brightness levels, it was then I noticed the screen doing what you show in your video. long story short I switched the accessibility option off & checked the blue light filter & saw it was switched on by default (at least it was on my device) now I never use this feature so I turned it off and reinstated the accessibility feature. Now no matter how dim or bright my display is it's stopped the green flickering. I did pass this on to Samsung as I feel it's a bug in the software. I have read multiple articles about this fault on reliable tech websites so it's a known problem. You probably don't use the extra screen enhancement accessibility option but thats how the fault manifested itself on my machine. While I'm taking about the colours the screen displays you can also apply sRGB picture enhancement in developer mode. sRGB shows an even more realistic colour gamut, making the best Samsung displays even more vibrant and colour accurate.
