Merge selected produces huge artifacts

[mkayi]

Hi,

I am working on an illustration with several layers, some grouped. I imported a few jpg files as  textures and background and used adjustment layers.

When I now select everything except the background, the result shows huge ( I mean like covering a third of the image) artifacts which look like random rectangles or a pixelated image, but with huge pixel, so to speak.

I found a few threads where problems with merged layers have been described, but never this, so I thought I'd open a new thread.

So, the behaviour I expect is this: The overall composite looks exactly like before, but all of the selected layers have been replaced by a single new one
The behaviour I see is attached below.

What is going on, here?

[mkayi]

Upon further investigaton I can say that the artifacts are produced by two Gaussian Blur adjustment layers which are attached to two single layers (they are only working on that single layer instead of all of the layers). When I exchange those for lense blur, the artifacts are gone.

Now, I get erratic bands of transparent color/value changes as an end result. Which is still absolutely not what I expect after merging

 

EDIT: More testing. If I merge just two layers starting from the bottom most and repeat this until I arrive at almost the topmost, I get the expected result. The topmost layer is a texture set to multiply at 59%. Nothing fancy. Still, when I merge that one with the remaining single layer I manually produced, it goes from what I expect to see (see first image above, what I am working on, basically) to what I attach below

 

Edited February 27, 2021 by mkayi

[Chris B]

Hey mkayi,

I'm not seeing this - can you try disabling OpenCL from Preferences > Performance and see if that stops it happening?