Fultext search on cifs external storage

Hello,
i have problem with fulltext search (or index) on external storage .
If i start indexing with

sudo -u apache /usr/bin/php /var/www/html/nextcloud/occ fulltextsearch:index

i can see NC go through the files.

After indexing, fulltext search finds files only by filename and not the contents. Indexing and search works fine for files directly in NC. I don’t want to move these files inside.

How can i troubleshoot this issue?

sudo -u apache /usr/bin/php /var/www/html/nextcloud/occ fulltextsearch:check
Full text search 23.0.0
 
- Search Platform:
Elasticsearch 23.0.0 (Selected)
{
    "elastic_host": [
        "http://localhost:9200"
    ],
    "elastic_index": "doc",
    "fields_limit": "10000",
    "es_ver_below66": "0",
    "analyzer_tokenizer": "standard"
} 

- Content Providers:
Files 23.0.0
{
    "files_local": "1",
    "files_external": "1",
    "files_group_folders": "1",
    "files_encrypted": "0",
    "files_federated": "0",
    "files_size": "10",
    "files_pdf": "1",
    "files_office": "1",
    "files_image": "0",
    "files_audio": "0",
    "files_fulltextsearch_tesseract": {
        "version": "22.0.0",
        "enabled": "0",
        "psm": "4",
        "lang": "pol",
        "pdf": "1",
        "pdf_limit": "0"
    }
}