Using custom WordPress permalinks can improve search engine optimization(SEO) and make your website's URL more attractive for searches. WordPress permalinks are the permanent URLs for your posts and pages.

If necessary you can reset WordPress permalinks to their default setting within the database.

Note: You should always backup your site before performing any troubleshooting.

Log into phpMyAdmin. Check article: https://help.tsohost.com/knowledge-base/article/11999

Click on the wp_options table.

Locate the permalink_structure entry in the option_value column.

Click the Edit button.

Under the option_value field for this entry, remove the text and leave it blank.

Click Go.

The URL on your website's pages should display the default permalink settings for WordPress.