for me every time I load the page - or do anything whatsoever that refreshes the page/notification, the red notification number will blink somethin random, like "7", or "15", just for a second, then disappear.
i did go to my chrome settings and under the timeframe "All Time", I cleared the option for cookies/data cache as well as cache images/files
no change to the flashing, except now it lingers for an extra half second or so.