My understanding is that those droplets contain millions of virus’ and those individual virus’ can go through the filter. So if they’re laying on the mask and the droplets dry those virus’ can get through ...
The way I understand it from my micro classes, virus is transmitted through droplets that have been aerosolized or by physical contact. If an aerosolized dropled evaporates on the mask, the virus can’t just float on air through the hole. Some bacteria and fungi can, however.