What potential security settings in Firefox could prevent PHP scripts from executing JavaScript correctly?

Potential security settings in Firefox that could prevent PHP scripts from executing JavaScript correctly include Content Security Policy (CSP) settings that restrict the sources from which scripts can be loaded. To solve this issue, you can adjust the CSP settings to allow scripts from the PHP server to execute JavaScript properly.

header("Content-Security-Policy: script-src 'self' 'unsafe-inline' 'unsafe-eval';");