[Resolved] GenerateBlocks Headline Block Issue

<b>Background of the issue: </b>
I am preparing an Elements Template for a Custom Posttype. When using the Generate Blocks Headline Block, I can either translate the content of the Block or the Dynamic Before Text using the following code I found on another post in your Forum. Here is the code:

<wpml-config>
  <gutenberg-blocks>
    <gutenberg-block type="generateblocks/headline" translate="1">
      <key name="gpDynamicTextBefore" />
      <key name="gpDynamicUpdatedDateBefore" />
    </gutenberg-block>
  </gutenberg-blocks>
</wpml-config>

Markup of a Headline Block in the DB:
<!-- wp:generateblocks/headline {"uniqueId":"2d5b779f","blockVersion":3,"display":"inline-block","spacing":{"marginBottom":"1em","marginTop":"1em"},"dynamicContentType":"post-meta","dynamicLinkType":"term-archives","termTaxonomy":"countries","termSeparator":",","className":"dynamic-term-class","gpDynamicTextType":"terms","gpDynamicLinkType":"term-archives","gpDynamicTextReplace":"Terms","gpDynamicTextTaxonomy":"countries","gpDynamicTextTaxonomySeparator":"","gpDynamicTextCustomField":"title","gpDynamicTextBefore":"Marine Species in "} -->
<h2 class="gb-headline gb-headline-2d5b779f gb-headline-text dynamic-term-class">Terms</h2>
<!-- /wp:generateblocks/headline -->

Link to a page where the issue can be seen: hidden link

<b>Symptoms: </b>
When the code is active, the 'before text' is not seen in the Advanced Editor. When the code is inactive, only the 'normal' headline content shows up. The same issue occurs on the frontend; only one of the two is being translated. I expected to see 'Marine Arten in Südkorea' but got 'Marine Species in Südkorea' instead.

<b>Questions: </b>
Why is the 'before text' not visible in the Advanced Editor when the code is active?
Why is only one of the two (either the content or the 'before text') being translated on the frontend?