You are probably right about this
(Did you know that uint8_t char_notification_enabled = 0; means STARTED)
However, I understand it in a different way so for you that is when char_notification_enabled =0; means its value is equal to false;
And when if(char_notification_enabled == 1) value of it by true;
I may have misunderstood, please help me on this!
Thank you!