Hej! I use the new Photoshop 25.1.0 and have a problem with gaussian blur and iris blur (it might also apply to other types of blur). I see the effect for example when editing 16-bit black and white images, and applying a blur with high amounts (say 100 pixels or 200 pixels). The blurred image has banding, the grey tones are not smooth as expected. If I instead switch to RGB 16-bit, I do not see the effect on a similar image. It should be pretty easy to reproduce, take a black and white 16-bit image (in my case it had a bit of noise), add gaussian blur with 200ish in radius. You should be able to see the banding in the preview. Turn off the preview, banding is gone, turn it back on banding again. Switch to 16-bit colour, apply the blur, no banding. I edit a lot of black and white images, so this is a big issue.
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