Didn't notice that so far.
Just something to add
- sometimes if I 'm in a area with bad signal (with a high chance to interrupt the connection) , prefer to watch the match from my other account, as a friend/supporter so not to loose the "auto-sub" if I lost connection, and intervene/log-in if the match is going the wrong way

- the game/program, recognize when you leave your match, go to another friend to support him and return to your match again. So it starting showing you your friends/supporters one by one again
That means, it's easy to set auto-sub (from nordeus I mean) when not watching the game anymore.