This is all very interesting to me. I am 65 in pretty good health and have noticed mild vibrations/tremors in my chest area for last few months but only while sleeping or in light state of sleep. I did have Covid for 1st time right around same time these sensations started but I don't know if it was before covid or after but suspecting after? The crazy thing is I started Paxlovid immediately upon testing positive and it kicked my covid almost immediately so I never had covid bad at all, just had symptoms for a couple days so definitely not long hauler type. I thought maybe this was from anxiety, which I have had (mild) for 30 years. But now I can't believe its from anxiety. This is so bizarre. Best to all.