After unlocking the desktop client with my password, a 2FA dialogue pops up to authenticate with either OTP or Yubikey, it starts launching browser tabs that display the 1password.com sign in interface, with a message that my session has expired. These pages are unusable because another tab will launch after a couple of seconds and steal focus. Closing all the tabs did not prevent more from opening, only quitting the 1Password desktop client halted them. Reopening the client triggered the same issue but I was able to complete the 2FA and close all launched tabs.
It's usable but was an unpleasant intro to your 2FA system.
1Password Version: 8.6.1
Extension Version: 2.3.3
OS Version: Kubuntu 21.10