I don't know, but i do have a informed suspicion. For over a Century zinc has been known to be an effective antiviral, and one of a very few treatments for the common cold that actually works. It fell into disfavor before the mid twentieth century because of a really annoying side effect. It can cause loss of ability to taste and smell. There was some fear that it could cause permanent damage to the olfactory receptors. It was primarily the result of zinc nasal spray for head colds, for which it was a very effective treatment.
It remains available in the form of cold-eeze lozenges, which is somewhat effective when used early in the course of the infection. Given the random scattered reports of this side effect of Covid, along with the random scattered types of home remedies, including zinc (and possible overuse of zinc), I suspect there may be a connection.
Not conclusive, just an informed suspicion.