Suddenly can't sign into iCloud.com on Windows desktop

Hello,

I often sign into iCloud.com on a Windows desktop at work and it worked this morning, but I'm suddenly running into an issue where it says "Failed to verify identity. Please try again." after I input my email address and password.

I've tried rebooting the desktop and removing it from the list of devices on my iPhone (it won't budge no matter how much I try to remove it, though) to no avail.

Does anyone have any ideas on how to solve this?

Thank you!