mpdf generation from slideshow fails to respect image sizes and therefore content overflow slides

• Usability
• Consistency
• Conflict of two features (each works well independently)

Export a pdf version of slides (using mpdf) from the slideshow fails to respect image sizes when within PluginFluidgrid, and therefore content overflows slides in some cases.

Example of code from a production site:

{slideshow theme="sky" transition="slide" transitionSpeed="default" backgroundTransition="none" controls="y" controlsLayout="bottom-right" controlsBackArrows="faded" progress="y" slideNumber="y" fragments="n" fragmentClass="grow" fragmentHighlightColor="none" autoSlideStoppable="y" alignImage="n"} ^Presentació a: https://foo/bar ^
{FLUIDGRID()}~~cyan:.~~ {DIV(style="text-align:left")}
__Apartats de la xerrada d'avui__ (''Xavier''):
1. Dades crues
2. Processat de dades d'un mes
3. Processat múltipes mesos
4. Ingesta Dades Fusionades a CityOS
5. Ús de les dades
6. Pendent: Errades en agregats esbiaixats
7. Altres (per qui vulgui saber més detalls ;-) 
{DIV}
{img fileId="4"}
---
{img fileId="5"}
---
{img fileId="6"}
{img fileId="7"}
{FLUIDGRID}

Slideshow displays images in the fluidgrid as expected:

However, the pdf version does get the images splitted in several slides/pages.

Similar issue reproduced here:
http://xavi-9794-6688.show2.tikiwiki.org/tiki-index.php?page=new_page
u: admin
p: 12345
In this show instance, nothing is displayed in the pdf.
Using latest 24.x branch: r79594 (Last Changed Date: 2022-01-22 14:46:09 +0100 - Sat, 22 Jan 2022)

This bug has been demonstrated on show2.tiki.org

Please demonstrate your bug on show2.tiki.org