I have a file of a puzzle I created in Inkscape for a "CNC type" cutting tool and there are extra lines that show up on the tool that are not there in the svg when opened in Inkscape.  I think I asked a similar question years ago but I don't remember if I got an answer on how to get rid of them.

Attached is the svg with the area circled and a picture of what my machine is seeing.  There are also several other extra lines in the picture.  There are no straight lines in the puzzle.

It looks like the document has combined many paths into a couple of master paths.

It's possible that the cutting software is adding a 'z' command (zone close) a the end of one of the paths. Not sure how that can be fixed.

I've removed some redundant stuff, and applied all transforms.

Not sure if this will fix it, but give it a try.

Some additional information and a question.  I don't like to use Adobe Illustrator to make a file, but if I open it in AI and save the file the extra lines go away.  My question is how did you remove the redundant stuff?  I could've removed it if I could see it.

When I open an svg file from an unknown source there are a couple of things I do first.

Look at the structure in the Object>Layers and Objects panel

When clicking on objects look at the status bar at the bottom of the screen.

If confused, open the Edit>XML Editor

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In the example file you uploaded, there were redundant groups that contributed nothing to the image and anchors tags.

I just deleted them whilst watching the image - it made no difference.

Reading the Object>Layers and Objects panel is good practise :)