The first time, I didn't even notice.
The second time I got a little upset, but thought that it was a one-time issue.
At the fourth time that it happens, I'm losing will to play lichess and move onto another platform.
It is impossible that I lose 4 rated games because the timer shows the opponent is thinking, instead he already moved and the time is flowing down for me... and I don't even know that.
I lost a lot of points in ranking because it happenend against lower ranked players.
I don't know if I'm willing to play again until this has been fixed. And for good.
EDIT: Happens on ANDROID