Review the network configuration screen from top to bottom. Ensure you did not leave the CA Certificate dropdown on "Use system certificates" if a specific certificate is required. Best Practices for Mobile Network Security

Older Android versions allowed bypassing certificate validation. Choosing this option leaves your phone vulnerable to spoofed networks that can steal your login credentials.

Use the built-in file manager to navigate to your folder and select the certificate file. For Samsung Galaxy Devices: Open your Settings app. Scroll down and tap Security and privacy . Tap Other security settings . Select Install from device storage . Tap on CA Certificate or Wi-Fi Certificate .

If you've been on this network before and have an expired certificate installed, it could conflict with the new one. Go to Settings > Security > Encryption & credentials > Trusted credentials and remove any outdated certificates under the User tab.

It is important to know how to manage your certificates, including viewing, removing, or clearing all of them.