"invalid link" on valid external image

[mprins]

when using markup:
[{{ https://www.hnd.bayern.de/webservices/graphik.php?cache=hnd&statnr=16401006&thema=hochwasser.meldestufen&wert=wasserstand&vhs=false&geber=0&.png?300&recache|Peilschaal (130cm min)}}]

it is rendered as (added linebreaks/formatting for legibility):

<div class="thumb2 tright">
  <div class="thumbinner">Invalid Link<div class="thumbcaption" style="max-width: 294px">
    <div class="magnify">
      <a class="internal" title="Groter" href="https://wild-water.be/dokuwiki/lib/exe/fetch.php?tok=b98fd0&amp;media=https%3A%2F%2Fwww.hnd.bayern.de%2Fwebservices%2Fgraphik.php%3Fcache%3Dhnd%26statnr%3D16401006%26thema%3Dhochwasser.meldestufen%26wert%3Dwasserstand%26vhs%3Dfalse%26geber%3D0%26.png" target="_blank"><img width="15" height="11" alt="" src="https://wild-water.be/dokuwiki/lib/plugins/imagebox/magnify-clip.png">
      </a></div><em>Peilschaal (130cm min)</em>
    </div>
  </div>
</div>

Note the <div class="thumbinner">Invalid Link<div class="thumbcaption" where the image tag should be

While using only the DW native syntax:
{{ https://www.hnd.bayern.de/webservices/graphik.php?cache=hnd&statnr=16401006&thema=hochwasser.meldestufen&wert=wasserstand&vhs=false&geber=0&.png?300&recache|Peilschaal (130cm min)}}

the image is succesfully rendered as:

<p>
  <a href="https://wild-water.be/dokuwiki/lib/exe/fetch.php?cache=recache&amp;tok=b98fd0&amp;media=https%3A%2F%2Fwww.hnd.bayern.de%2Fwebservices%2Fgraphik.php%3Fcache%3Dhnd%26statnr%3D16401006%26thema%3Dhochwasser.meldestufen%26wert%3Dwasserstand%26vhs%3Dfalse%26geber%3D0%26.png" class="media" title="https://www.hnd.bayern.de/webservices/graphik.php?cache=hnd&amp;statnr=16401006&amp;thema=hochwasser.meldestufen&amp;wert=wasserstand&amp;vhs=false&amp;geber=0&amp;.png"><img src="https://wild-water.be/dokuwiki/lib/exe/fetch.php?w=300&amp;cache=recache&amp;tok=e51b7f&amp;media=https%3A%2F%2Fwww.hnd.bayern.de%2Fwebservices%2Fgraphik.php%3Fcache%3Dhnd%26statnr%3D16401006%26thema%3Dhochwasser.meldestufen%26wert%3Dwasserstand%26vhs%3Dfalse%26geber%3D0%26.png" class="mediaright" loading="lazy" title="Peilschaal (130cm min)" alt="Peilschaal (130cm min)" width="300">
  </a>
</p>