I started having that problem since the last update of the battle.net app (which looks awesome by the way, great work !).
The problem is that the settings window is not wide enough, and it’s not resizable. When I go to the notification panel, I cannot see whether the the sound notifications are active or not when the option is a checkbox. (You can find a pitcutre here :
https://imgur.com/Qd8t3Yh).In English, that problem does not exist but when switching back to French, the content does not fit in the window anymore. I think that just making the window resizable would be a nice option to solve that problem.