I don't know NoteSelf, so it's just a guess. But as you describe it, it seems to be an initialization problem. So the $:/macros/tasklist is not available, when the macro is rendered. ...
You may put a "NoteSelf" prefix to your topic title, to better catch Danielo's (author of NoteSelf) attention.
Or file an issue at
https://github.com/NoteSelf/NoteSelf.github.io/issues, where he will see it for sure ;)
-m