GGR from Image

[Krikor]

Hello guys!

I thought it best not to open a new topic since in part the question is somewhat the same.

I've been familiar with creating gradients from part of images for some time now. Either via Sample Gradient Along Path or via Gradient from Image... (plugins/script found in the gradient window).

However, I've been trying to create a gradient from a small image (27x12 px) for hours without being able to create the correct gradient.

I tried with the path both the exact width of the layer, and with a path a few pixels longer.

I made several attempts with both Sample Gradient Along Path and Gradient from Image.

I tried the tip from rich2005 about the option of G'MIC - Gradient from Line, but I believe that this filter is buggy.
As in meetdilip post #10, the preview displays a similar error. However if I uncheck the "Preview Gradient" option the error message disappears and it is possible to interact with the filter by adjusting the line to collect the gradient.

But even though, after adjusting the filter I manage to create an image identical to my original image, the .ggr is not created.

I searched for . ggr that was supposed to be created, either by refreshing the gradients window several times, or by checking the Gimp's gradient folders, and was not found.

I restarted Gimp, I think I read meeddilip say that this made the . ggr appear for him. It didn't work here.

Pixlab suggested updating the G'MIC, but that's what I happened to do a few days ago. I have version 3.1.6 at the moment.

In short:

How to get a gradient that exactly reproduces the gradient of the image below (Top - Original - the desired one).
   
After the top (original) gradient, here are 3 examples of other gradients that I have gotten in my attempts.

Thank you very much in advance!