Bypass 403 Single-Tab Restriction

I regularly work on a website that locks me to one tab and instantly throws a “403 Multiple tabs not allowed” message if I open a second page. I have no access to the server-side code, so all changes have to be made client-side... (Budget: $10 - $30 USD, Jobs: Google Chrome, JavaScript, PHP, Web Development, Web Scraping, Web Security, Web Testing, WordPress)