yosh

restarted, tried incognito mode, deleted certs - nothing seems to work :(

That's a new error — fascinating! Can you try to run this: certutil -L -d ~/.mozilla/firefox/[xxxxxx].profile (Where [xxxxxx] is some random hex string)

Back behind my computer. Getting the following error: "certutil: function failed: SEC_ERROR_BAD_DATABASE: security library: bad database."

Thanks for checking. Is there a cert9.db (or cert8.db) file anywhere in the Firefox profile directory?

Wondering if it's a conflict with another record in the DB, or a version issue between certutil vs Firefox NSS. Hmm, could you try it on a new Firefox profile? (Close Firefox, rename ~/.mozilla.backup, and start Firefox again to create fresh profile.)

That worked!

Well, it's a start. Need to reproduce some of these version issues. Suspect there is all kinds of profile migration glitchiness from older Firefox versions.