Adjusting the elvis operator for thumbnail_uri_remote condition.

src/Plugin/media/Source/Asset.php

@@ -262,7 +262,7 @@ final class Asset extends MediaSourceBase {
         return $this->getLocalThumbnailUri($asset_id, $version_id, $external_id);
 
       case 'thumbnail_uri_remote':
-        return $asset['thumbnails']['600px']['url'] ?: $this->getRemoteThumbnailUri($external_id);
+        return $this->getRemoteThumbnailUri($external_id) ?: $asset['thumbnails']['600px']['url'];
 
       case 'file':
         return $this->assetFileHelper->downloadFile(