Can't connect to torproject.org

[Celejar <celejar@gmail.com>]

I feel silly for not being able to figure this out.

I can't connect to torproject.org via either Firefox or Chromium. The
browsers object that HSTS is in place and they don't recognize the
site's certificate (SEC_ERROR_UNKNOWN_ISSUER). There's no opportunity
offered to add an exception.

I've seen these threads:

https://support.mozilla.org/en-US/questions/1201504
https://superuser.com/questions/1066863/how-can-i-add-a-certificate-exception-for-an-hsts-protected-site-in-firefox
https://support.mozilla.org/en-US/questions/942924

But I don't see any good suggestions for fixing this in my case. I have
a pretty standard Debian installation, with standard certificates
installed, and no customization to my local certificate infrastructure.
I'm connecting via Verizon FioS, with no proxy in use (on my end, at
least).

Celejar