Let's see if Koala have some fix to this problem instead of a workaround. But thanks for the suggestion.
Discussion
Yeah, it's not ideal, but it's a decent temporary solution. It's still better than manually clearing each notification individually.
Rhat is qeird that notification shouldn't be sticky, it's not defined like that and not behaving like that in my Grapheme, can you try disabling the "Relays Connection" notification?