Attempting to use Microsoft teams with shields enabled, will cycle and not load and producing an error message. "To open the web app, you need to change your browser settings to allow third-party cookies."
https://teams.microsoft.com/go


Easily enough.
Tested in Brave Release/Beta/Nightly.
Screenshots from Brave Nightly; Version 0.72.11 Chromium: 77.0.3865.65 (Official Build) nightly (64-bit)
Tried some referrer whitelisting, this didn't help.
The login process has a few browser redirections involved between various domains.
https://login.microsoftonline.com/ -> https://login.live.com/ -> https://teams.microsoft.com/
skype.com and/or msftauth.net maybe related, not sure.
Seems the removing the cross-site cookie specifically on https://teams.microsoft.com/fixed the issue.
@ryanbr : could you please elaborate a bit? Where did you remove a cross-site cookie?!
I seem to be unable to access teams using brave.
Same here.
@nils-a In the sheilds menu, in the url-bar. Set it to allow Cookies.
I missed that in your ScreenShot:

accessed URLs during login: https://api.spaces.skype.com, https://statics.teams.microsot.com, https://browser.pipe.aria.microsoft.com https://jp-prod.asyncgw.teams.microsoft.com https://trouter2-easia.trouter.teams.microsoft.com/ https://jp.msgapi.teams.microsoft.com https://go.trouter.teams.microsoft.com https://jp.ng.msg.teams.microsoft.com/ https://config.teams.microsoft.com/ https://browser.pipe.aria.microsoft.com/ https://aadcdn.msftauth.net/
I can not get a success with cookies settings for these. It works by allowing these and SSO site in my company .
Here are the cookies listed once you enable third-party cookies:
FWIW, these exceptions work for me

Hi,
any update on this? Even office365 applications do not work properly with brave shield enabled.
Most helpful comment
I missed that in your ScreenShot:
