Verification Failed: Unknown error

My Macbook Pro (15′, Early 2015, Catalina 10.15.4) suddenly cannot log in to iCloud. I decide to log off and try to log in again. However I got the "Verification error: Unknown error occurred" when trying to log in.

Checked Console and got the following error:

An unexpected error occurred: Error Domain=com.apple.accounts Code=12 UserInfo={NSLocalizedDescription=<private>, NSUnderlyingError=0x7fedda5bde10 {Error Domain=com.apple.accounts.keychain Code=-67680}}

Anyone has any idea what causes this? Google does not seem to give much help.

EDIT: cloudd asked for password a few days ago, because I keep force quit the process as it takes 150% GPU power and the fans keep spinning, even when not in use. Decided to deny them permission because I thought it was a malware problem. A few hours afterwards the problem above occurred.