@lee.cocklin

I was able to resolve the issue with this patch:

diff --git a/modules/contrib/views_merge_rows/src/HookHandler/ViewsPreRenderHookHandler.php b/modules/contrib/views_merge_rows/src/HookHandler/ViewsPreRenderHookHandler.php
index 81b963527..b904b6e24 100644
--- a/modules/contrib/views_merge_rows/src/HookHandler/ViewsPreRenderHookHandler.php
+++ b/modules/contrib/views_merge_rows/src/HookHandler/ViewsPreRenderHookHandler.php
@@ -849,7 +849,14 @@ protected function renderMerge(
     }
     unset($iteration, $value_count);
 
-    $view->style_plugin->setRenderedField(\implode('', $merged_row[$field_name]), $row_index, $field_name);
+    $html_string = implode('', $merged_row[$field_name]);
+    $render_data = [
+      '#markup' => \Drupal\Core\Render\Markup::create($html_string)
+    ];
+    $html_string = \Drupal::service('renderer')->render($render_data);
+
+
+    $view->style_plugin->setRenderedField($html_string, $row_index, $field_name);
   }
 
   /**