Magento Catalog Search Not Working Properly

1. Clear Magento cache

1. Log into your Magento Admin
2. Navigate to System > Cache Management
3. Click on Flush Magento Cache

***Note: You can disable the cache you want if you are in development mode.

This is the guide that shows you how to enable/disable OR clear cache in Magento 2.

2. Reindex Data

You can try to reindex your data, it might help somehow.

1. Log into your Magento Admin
2. Navigate to System > Index Management
3. Click on Select All in the left and select Reindex Data in actions drop-down
4. Click on Submit to reindex.

3. Back to Magento Base Theme

• If your search is working with Magento Base Theme, there might be a code problem with your custom themes. In case it is working, you need to compare to see if you might miss any codes in app/design/frontend/base/default/layout/catalogsearch.xml to app/design/frontend/default/your_theme/layout/catalogsearch.xml.
• Or you can do another test by deleting the catalogsearch.xml of your theme from the directory to see the search is working. Remember to backup the file before start the process.

4. Check product attributes

1. Log into your Magento Admin
2. Navigate to Catalog > Attributes > Manage attributes
3. Search for name attribute and configure it like below
   

   

4. Search for sku attribute and configure it like below
   

   

***Note: Make sure that the scope of name attribute and sku attribute are set to Global.

5. Change the configurations of Search

1. Log into your Magento Admin
2. Navigate to System > Configuration
3. Click on Catalog > Catalog Search and configure it like below
   

   

Read more:
How to Configure Search: Catalog Search in Magento 2