The effect of the pandemic so far has been deflationary:...

The effect of the pandemic so far has been deflationary: everything is losing value, and gold stocks are just stocks in that environment. Gold is just a commodity, losing value with other commodities. It has fallen a little, but there's fear that it will fall a lot. For every company amid the pandemic there are also new risks like "what if the virus spreads through the workers" and "what if nothing can be shipped due to lockdown" and so on.

What gold may respond well to is an inflationary response from central banks, i.e. massive interest rate cuts (possibly into negative territory) and money printing to try and keep an economic spark going. That could positively affect gold stocks, but at the moment, the mood is that all stocks are bad unless they're in the business of defeating the virus or burying the dead....