Hey RGB,
first of all, thank you for the purchase!
Yes, it is indeed a bug – please accept my apologies for any inconvenience and thank you for reporting! I’ve prepared a fix, which you can download here. Please download the archive, unzip it, and upload the contained file into the theme folder (/wp-content/themes/Kanso/), replacing the existing file. The menu links outside the one-page template should work like in the theme demo now. Let me know if it helps, and please tell me which version of the theme you have, so that I could update the ThemeForest version accordingly. Thanks!
Sincerely,
Andrii / Satori Studio