Discrepancies between filter preview and result

Hello, this has been annoying me for some time now, but now, it really is extreme.
Filter preview:


As you can see, the two results are significantly different. What is going on?

I would need to have a look at the filter code?

It’s very amateurish, sorry.

Not sure what was causing the distortion. But it wasn’t working from a Custom Parameter at all. I cleaned it up and added support for customParameterString.

Thanks a lot for taking a look, but I’m afraid the preview and the result are still completely different, like in the screenshot above.

For most contours, the discrepancy is not too annoying, although I always notice a slight jump between the previews contours and the result every time I click “Apply” on the filter, but it’s usually not more than one or two units per node. For some reason, on the outlines above, the difference is enormous and makes the filter useless.

Then you need to send me the file. My test file was fine.

It happens on every file, albeit not with as extreme a discrepancy as on the glyph shown. I’ll send you the file.

Screen Recording 2023-06-01 at 16.36.50

As you can see, there is a jump when I hit Apply.