Well this plugin is paid, so I can't take a look into the code.
But there are several other plugins around that can make any text above events. Maybe you can try them.
I do plan on doind that kind of plugin, for a long time ago haha. Don't know when I will do it then. But I let you know if I did. For now, I guesss you either need to change the way you want to show the text above the event:
1 - Not using self variables
2 - Using another self variable plugin that is compatible with sang hendrix
3 - Using another event label/text plugin that is compatible with my self vfariables