Thanks for this hint! Yes this was the problem. Switching to software openGL with "openGL switcher" application solved the problem.

For me this problem is solved.

When I try to export a simple plot

figure();
plot([0,1],[0,1],'x');
print 'test.svg' -svgconvert

Octave runs forever and creates a huge temporary file that quickly becomes > 100 GByte if I don't kill the process. The GPU runs on 50% load and two out of 8 physical cores are on 100% load.

When I copy the temp file before stopping octave, I can see that it is svg-code.

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns="http://www.w3.org/2000/svg"
     xmlns:xlink="http://www.w3.org/1999/xlink"
     width="418pt" height="314pt" viewBox="0 0 418 314">
<title>Figure 1</title>
<desc>
Creator: GL2PS 1.4.2, (C) 1999-2020 C. Geuzaine
For: Octave
CreationDate: Wed Jun 28 14:30:02 2023
</desc>
<defs>
</defs>
<polygon fill="#ffffff" points="0,0 418,0 418,314 0,314"/>
<g>
<polygon fill="#ffffff" points="0,314 418,314 418,0 0,0" shape-rendering="crispEdges"/>
<clipPath id="cp00418314">
  <polygon points="0,314 418,314 418,0 0,0"/>
</clipPath>
<g clip-path="url(#cp00418314)">
<polygon fill="#ffffff" shape-rendering="crispEdges" points="54.4343,23.5533 54.4335,23.5569 54.4608,23.5577"/>
<polygon fill="#ffffff" shape-rendering="crispEdges" points="54.4335,23.5569 54.4327,23.5605 54.46,23.5613"/>
<polygon fill="#ffffff" shape-rendering="crispEdges" points="54.4608,23.5577 54.4873,23.5621 54.46,23.5613"/>
<polygon fill="#ffffff" shape-rendering="crispEdges" points="54.4335,23.5569 54.46,23.5613 54.4608,23.5577"/>
<polygon fill="#ffffff" shape-rendering="crispEdges" points="54.4327,23.5605 54.4319,23.5641 54.4592,23.5649"/>
<polygon fill="#ffffff" shape-rendering="crispEdges" points="54.4319,23.5641 54.4312,23.5677 54.4585,23.5685"/>
<polygon fill="#ffffff" shape-rendering="crispEdges" points="54.4592,23.5649 54.4858,23.5693 54.4585,23.5685"/>
<polygon fill="#ffffff" shape-rendering="crispEdges" points="54.4319,23.5641 54.4585,23.5685 54.4592,23.5649"/>
... sequence never ends

After a normal svg header I get a sequence of infinite polygon fills with "crispEdges".

After adding the -nosvgconvert option to print command the problem persists.