Hey there,
its not really a bug but the small icon is glitched. It also happened in a earlier supernotes version.
Im currently on Ventura 13.5.2. I already re-installed it a few times.
All the other icons are working.
Hi @Kyumie, welcome to the Supernotes Community! 
We’ve not noticed this before and are looking into this. If anyone else is experiencing this issue please let us know!
This was an issue with Supernotes 3.0.2 and has since been fixed