I’ve been using darktable for a while but I am no expert.
I use a Fuji X-T30 and find that my raw images look very dark after import.
After looking around, I found that some 3D LUTs (see an attached example) and started using them together with a bunch of other adjustments to make the raw image look a little better.
I am now finding that the application of these LUTs causes a weird block pattern after I apply them. It is not consistent and sometimes disappears after zooming in / out. Changing the interpolation method did not help.
See an example in the attached images.