I set up telepathy with my Google account, and initially all worked well. However, after changing my Google password, I can no longer connect. Obviously, I can't authenticate with the old password, but AFAICT there is no mechanism to provide the new password to kaccounts. Using KF5 (kaccounts-integration-16.12.3-1.fc25.x86_64). I had to use an older (KDE4) computer recently, and when it failed to connect, it popped up a dialog asking for my password, after which it is again working flawlessly, making this appear to be a nasty regression.