I've never had it happen the same way with a flu/cold. If I lose smell to a flu/cold, it's because my sinuses are clogged up with snot. With COVID my sinuses were completely clear. I could breathe just fine through my nose - I just couldn't smell anything.

It seemed like a neurologically-induced loss of smell, like my brain was malfunctioning. A couple days after losing my sense of smell, I realized I actually could smell intense things for a second, like the fire cider I made last year. That stuff is crazy strong smelling from vinegar and a ton of very strong herbs and spices. The weird thing though was I could only smell it for a few seconds, then the smell would vanish again. I couldn't smell the fire cider again unless I waited at least a few minutes. It's like the part of my brain that controls smell was shorting out.