I installed elasticsearch and the Magento backend connection test to elasticsearch is successful. If I save settings, clear the cache and reindex as described in the Magento devdocs, all product cateogries are empty and my search function has no result, whatever I type in there. I can still access the products with the direct url, thats all. If I switch back to MYSQL as search engine and clear the cache all products are back. Both Magento and Elasticsearch are Ubuntu18.04 servers, Magento 2.3.2 and Elasticsearch 6.8.3. Any idea where I can take a deeper look or how this problem can be solved?
EDIT: Some product attributes were not enabled for search (but not all! So there must have been results before). I reindexed and now the ES shows very good results! But as before, product pages are empty.
EDIT 2: Its a Multistore. The website id 1 works with ES, all other websites have no search results – and everywhere empty categories.