“CNN is of course a great authority on and a source of unbiased reports on Russia but a grain of salt is advised here as well as comparative perspective.”

Russia is not a great source of unbiased reports on Russia. Is CNN any better? Who knows, but reporting accurately on Russia is like reporting accurately on China: you get what you can. But yes, COVID positive tests and deaths are most likely under reported or at least reported a week or two later than they actually are (these are #s from two weeks ago).