Google Drive connected app not working on macOS
As @hbaldwin mentioned this issue on Linux, I have the same problem with Vivaldi for Mac, I'm using Chrome instead to deal with this. This problem is present since version 1.6.
I suspect drive - both app and extension - won't work in vivaldi. They use chrome sync, not supported in vivaldi and google is probably blocking any other chromium based to use its own apis. Older version of drive probably were working probably due lack of this restriction.