When I move lightroom from my laptop screen to my monitor, the images look substancially more noisy. It seems to be all images but does not seem to be a grainy-ness of the monitor since the grainy pixel move with the image. I did check that it is not just that the image is bigger on the screen and therefore you can see more grainy-ness.
Details: Monitor: LG 27UL650 27" 4k IPS monitor. Calibrated with SpyderX.
Laptop: Lenovo 4K 15" Oled screen
Photos: Raw from Sony A7rii with ISO 1200 or lower.