There could be several reasons why you can’t access your WordPress dashboard, even with the correct username and password. Here are some troubleshooting steps to consider:

1. Clear your browser’s cache and cookies: Sometimes, your browser might have saved incorrect or outdated information. Clearing your browser’s cache and cookies can often solve login issues.
2. Try a Different Browser or Incognito Mode: To ensure that the issue is not browser-specific, try using a different browser to log in. Alternatively, you can also try to log in using your browser’s private or incognito mode.
3. Reset your password: Use the “Lost your password?” link on the login page to reset your password. You’ll receive an email with instructions on how to do so.
4. Disable Plugins: Sometimes, a plugin can interfere with the login process. If you have access to your website files, you can manually disable all plugins to see if this is the issue.
   • Access your website files using FTP or your hosting provider’s file manager.
   • Navigate to /wp-content/ directory.
   • You will see a folder named plugins. Rename this folder to something like plugins.old. This will deactivate all of your plugins.
5. Switch to a Default Theme: If a theme is causing the issue, switching to a default WordPress theme can help. If you can access your website files, you can manually change your theme.
   • Access your website files using FTP or your hosting provider’s file manager.
   • Navigate to /wp-content/themes/ directory.
   • You will see folders with the names of your themes. Rename the folder of your current theme. This will deactivate your theme and WordPress will automatically switch to a default theme.
6. Check .htaccess file: A corrupted .htaccess file can prevent you from logging into your dashboard. Rename your .htaccess file and try logging in again. If this solves the problem, you can regenerate a new .htaccess file by going to your WordPress admin area and visiting Settings > Permalinks.
7. Check Database Prefix: If you or someone else has recently carried out work on the database and changed the database prefix, this could cause login issues.
8. Use wp-config.php trick: If you still can’t login, try to add the following lines of code to your wp-config.php file:

define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');

You should replace http://example.com with your own URL. Also, be sure to add these lines above where it says: /* That's all, stop editing! Happy blogging. */

Remember to backup your site and database before performing any of these troubleshooting steps. If you’re unsure about any of these steps, please contact your hosting provider’s support for assistance.