What the heck is that smell?

Hi all. Is phantosmia common amongst folks here? Essentially smelling something you know is not present. Smells are typically of something burnt, smoky, or foul but can be pleasant. I seem to have had that a few times these last couple of weeks.

I had this about 6 months before my first sign of MS.
I always believed I had covid in Nov 19 and this was an after-effect. I still get this on occasion.