Read this blog on Amasty Elasticsearch not working for more information.
There are several reasons why Magento 2 search doesn’t work as supposed. Let’s see how to solve the most common issues.
It is required to make sure that all the necessary configurations were made.
First of all, please check what search engine is selected for your site in default Magento settings:
Stores > Configuration > Catalog > Catalog > Catalog Search > “Amasty Elasticsearch”
Secondly, check the general settings of the extension:
Stores > Configuration > Amasty Extensions > Elastic Search > Search Engine > “Amasty Elasticsearch”
Then, click “Test Connection” button and make sure that you see “Successful! Test again?” message.
Steps to Fix
1. Clean the cache
Solving any problem you always start with the same action of cache flushing. For this, go to System > Cache management > Flush Magento Cache. If this doesn’t help, move to other points from our list.
2. Check search configurations
Another common solution of a not-working search in Magento 2 stores is just setting up the right configurations. For this, navigate to Stores > Configuration > Catalog > Catalog Search and set 1 in the Minimal Query Length line and 128 in the Maximum Query Length line.
Then enable search suggestions and set 2 in the Search Suggestions Count line. Don’t forget to save the changes and flush the cache.
3. Make data reindexing
Sometimes you may get issues with the search if your Magento doesn’t index properly. So reindexing can help you with the problem. To do this, open System > Index management, then select all points with the mass action and choose Update on save form the Actions dropdown.
4. Add or set search by synonyms
To make search results more relevant, you need to enable search by synonym functionality. For this, go to Marketing > SEO & Search > Search Synonyms. Next, click on the New Synonym Group button to create a new group of synonyms. In the opened page, specify the scope and enter the synonyms separating them by commas. Then save the changes and check the result on the frontend.
If these methods do not fix the Amasty Elasticsearch not Working issue, then you should switch to another search extension like this one. It will give all the features and more as Elasticsearch but can be completely customized without any coding.