Cant access Photos, Notes, Reminders, Pages or Numbers on ICloud.com

Hello and Merry Christmas,

I noticed the problem today when I tried to download a video via Icloud.com. My Photos App just says: Cannot Load Library - Photos was unable to load your photos and videos. Then I clicked around and noticed, that many other features were gone, too. Reminders gave me this error message:

ACCESS_DENIED","reason":"private db access disabled for this account","ckErrorCode":"ACCESS_DENIED"

Pages and Numbers just say: There was a problem loading your data for this application.

Notes just doesnt show anything at all.

Icloud in general is very very slow, on Iphone as well as in the browser.

I tried many different things, including:

Switching browser

Switching device

Switching from Wifi to Mobile Data on IPhone

Signed off Icloud account and back in on IPhone

The issue is still there.

Searching for this issue just gives me some threads from back in 2016 (https://discussions.apple.com/thread/7519160) . They had the same issue and for some reason, there was no real answer there, so I am creating a new thread.