Inlining SVG's not working on Unix Server but External SVG's ok

Hi there,

we are using Apache FOP to generate PDF's & have an issue with SVG's.

To include an SVG we're using something like the following...

|<fo:block> <fo:external-graphic src="classpath:image/MyImage.svg" 
content-width="150mm"/> </fo:block> |

The above works fine in all environments.

Now I'm trying to inline an SVG in the Stylesheet, like this...

|<fo:block> <fo:instream-foreign-object content-width="272.6mm"> <svg 
xmlns="http://www.w3.org/2000/svg" width="780" height="120" viewBox="0 0 
780 120"> <g style="fill-opacity:0;stroke-width:2;stroke:black"> <rect 
x="2" y="2" width="254" height="99"/> <rect x="256" y="2" width="485" 
height="99"/> </g> </svg> </fo:instream-foreign-object> </fo:block> |

That works OK under Windows, but when deployed on our Linux Server, 
seems to do nothing.

I have read some comments on the Apache FOP Website about it using 
Apache Batik to render SVG's
and that this requires a Graphical Environment, so will not work in many 
Unix configurations.

What I don't understand is, how come the external SVG is working ok on 
the Unix Server & inline is not?

Also, the Apache FOP Website recommends a Tool called PJA toolkit 
<https://www.eteks.com/pja/en/> to workaround this issue,
but it looks very dated, so I wonder if its going to work with our JDK 17?
(and indeed its developer, Emmanuel Puybaret, is quite surprised anyone 
would still be recommending use of this tool)

I would be grateful if anyone has some Info about this.

All the best,
Dave