Re: NVDA saying unknown again in browsers
Have you tried restarting NVDA with all add-ons disabled and seeing if the issue persists? If not, try that. If the issue stops, then use Add-Ons Manager to disable (but not remove) all of your add-ons and then re-enable them one by one until the issue recurs.
Brian - Windows 10 Pro, 64-Bit, Version 1909, Build 18363
Science has become just another voice in the room; it has lost its platform. Now, you simply declare your own truth.
~ Dr. Paul A. Offit, in New York Times article, How Anti-Vaccine Sentiment Took Hold in the United States, September 23, 2019