Score doesn't update if "display in leaderboard" is not checked

Hello. I have a problem where my statistic is only updated if the option "display in leaderboard" is checked. I want it to update it without showing it to the player, as it is not a number players should compete for, just a variable which value I want to retrieve in later sessions.

Regarding cookies, I don't want to use them as their behavior is inconsistent across browsers. Also, saving in statistics has the plus advantage of players being able to save their value permanently.