After I retired, I consulted at a bank and it didn't take much to block a site. It blocked most everything from youtube to news sites if the titles contained certain string values. IT also had a verification process on certificates.
The worst part was that your manager had a list of sites you tried to go to and got blocked. I had programmers reporting to me that needed access so it was easy to release a site as I had high clearance. I would not want and try and surf as a clerk.
Check with IT as to why. It might be easy to fix.