As I mentioned, the burning cigarette smell started what I termed "several years ago." That very well could have been March 2020 when a Binax test indicated I had covid. I never connected the two. I also got covid last September and that could explain the intermittant episodes since my surgery in November. Thanks for sharing your story. It is well documented that many people lose their sense of smell with covid and perhaps the experience of smelling something burning is a variation of that.