No search results of indexed PDF

Hi
Before I was still on Joomla!1.5 and used "PDF Indexer".
Migrating to Joomla!3.9.18 I found your OS PDF Indexer which should do the same (without EDocman).

After installation, activation of the 2 plugins and indexing all documents I will not get any results in simple Search and Searchindex.
What I missed?

BTW:

1. PHP is still on version 5.6.40 but will be upgraded next by the provider to 7.2.
2. error_log
   • PHP Strict Standards: Only variables should be assigned by reference in .../plugins/search/doc_indexer/doc_indexer.php on line 99
   • PHP Strict Standards: Only variables should be assigned by reference in .../plugins/search/doc_indexer/doc_indexer.php on line 41
3. administrator/error_log
   • PHP Strict Standards: Only variables should be assigned by reference in .../components/com_docindexer/helper/helper.php on line 55
   • PHP Strict Standards: Only variables should be assigned by reference in .../components/com_docindexer/helper/helper.php on line 146

Hi Bruno,
Please submit ticket and send your site url with super admin account. I will check the issue for you
Thanks
Dam