We are currently considering using Firefox ESR as our default browser but experiencing a few issues and one of them is with our configured SailPoint IdentityIQ Single Sign-On Experience, which uses Basic Authentication. Issue Description First, the login button needs to be clicked multiple times before access to the site is granted. Once signed in, the Firefox inbuilt authentication dialogue appears, prompting the user to log in again (see the attached screenshot). The landing page is only presented after clicking the login button several times. This creates a poor user experience, sometimes causing pages to load improperly. Interestingly, the same process works seamlessly in Edge Chromium. Troubleshooting Steps Taken I have already attempted the following: 1. Temporarily disabled all custom and security settings in mozilla.cfg and config.json. 2. Temporarily disabled Firefox Tracking Protection. 3. Allowed third-party cookies for the specific URL. 4. Upgraded Firefox Version to 128.7.0 5. Since our Firefox browser is significantly hardened, I have also enabled and reconfigured the following settings in mozilla.cfg to ensure Basic Authentication is allowed, functions properly, and suppresses Firefox’s authentication prompt, but without success: network.http.phishy-userpass-length = 255 network.http.use-basic-auth network.automatic-ntlm-auth.allow-non-fqdn network.automatic-ntlm-auth.trusted-uris security.enterprise_roots.enabled security.enterprise_roots.enabled Observations from SailPoint Team Our colleagues from SailPoint have tested the setup in their environment, and according to them, it works as expected. However, their browser is not hardened, and they have leveraged the SailPoint UI for authentication instead of the built-in Firefox authentication prompt. Further Investigation • Is there a specific configuration required in the user profile settings? • Network trace analysis shows 404 errors on GET requests and the following error codes on POST requests: • 302 Redirect: Mozilla Documentation • 408 Request Timeout: Mozilla Documentation Next Steps Is there a specific security setting that needs to be enabled or disabled? Are there any particular Firefox enterprise policies we should modify? I have also attached screenshots for reference. Let me know if you need specific logs or network traces for further troubleshooting.