That would make sense if it was only subtitles showing up late (lagging) and then blinking out the moment they're meant to go off anyway. But we also have subtitles that appear to show up on time, and blink out immediately. It would also make more sense if the subtitles were showing up randomly late. If a subtitle is meant to be up for 2 seconds, lag would mean it would randomly show up at any point during those 2 seconds. Meaning you wouldn't just see subs blinking on and off, you'd see subs that come on and just don't last as long as they should. e.g. it's a .5 second late so it's only up for 1.5 seconds making it a quick read. These are always blink on and off.