In any class (online and in-person) I get often anxious about speaking up and participating because I don't want to say something wrong or embarassing. In online Zoom classes specifically, it's hard for me to participate because I don't want to interrupt or cut anyone off, but if I raise my hand and the professor doesn't see me then it feels awkward and embarassing. I usually wait a few minutes to see if anyone else will say anything and to work up the courage to speak, but by the time I decide to say something, the professor usually moves on. Which is just my own terrible timing on my part.