Once trying to access Office 365 OneDrive browser loads the structure and list of folders but when trying to access some of the folders it doesn't work and it takes significant time when it's accessible.
It works properly and seamlessly in the Chrome browser.
I'm using following version:
Vivaldi 1.5.658.56 (Stable channel) (64-bit)
OS Mac OS X
User Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.100 Safari/537.36 Vivaldi/1.5.658.56