Re-edit leads to 'nojs' in stead of 'ajax'

Greate module, thank you!

Since the Drupal core update to 8.6.9, re-edit a newly created paragraph or editing an edited paragraph, leads to a Symfony error:

<em class="placeholder">LogicException</em>: The controller must return a response (Object(Drupal\Core\StringTranslation\TranslatableMarkup) given). in <em class="placeholder">Symfony\Component\HttpKernel\HttpKernel-&gt;handleRaw()</em> (line <em class="placeholder">169</em> of <em class="placeholder">vendor/symfony/http-kernel/HttpKernel.php</em>). <pre class="backtrace">Symfony\Component\HttpKernel\HttpKernel-&gt;handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session-&gt;handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle-&gt;handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache-&gt;pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache-&gt;handle(Object, 1, 1) (Line: 84)
Drupal\shield\ShieldMiddleware-&gt;handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware-&gt;handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware-&gt;handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel-&gt;handle(Object, 1, 1) (Line: 693)
Drupal\Core\DrupalKernel-&gt;handle(Object) (Line: 19)
</pre>

The problem is caused in the GeysirModalController methods where the $js parameter has a value of 'nojs' when closing the dialog.