My Boss wanted to See the Sourcecode of a Website once. So I opened it.
Boss: what Browser is this?
Me: Mozilla.
Boss: Do you have Firefox?

... thank god IT was only an internship.

Welcome home!

Well Mozilla isn't a browser, Firefox is. Mozilla is just the company behind it.
Or do you browse with Google instead of Chrome?

@Torbuntu by you saying it works fine at home, I assume it's not working at office. That's probably a certificate issue. Get your office VPN certificate and import it to Firefox's certificate manager.
Firefox has its own certificate manager while Chrome/edge/IE use the common windows certificate manager. You should find the certificate there and export it.

@Torbuntu what was the config to be changed called?

@Torbuntu oh! I've never heard that as 4. Isn't it 3 by default?
Is it tls1.3 with max version as 4?
Why would max version as 4 be a problem anyway?