Today I wondered how to remove an annotation in RQDA. It turns out, all you have to do is click on the annotation to view it, remove the text of the annotation (completely), and then save it.
Sociologist. Social inequalities. Discrimination. University of Neuchâtel.
Didier Ruedin 
It took me a while to figure this out because I had a syncing conflict (which I was not aware of at the moment), and my changes were not saved: whenever I tried to remove the text and save this, the annotation was still there. That’s a different problem, though.