Understanding WCAG2.0

For security reasons, there may be a mechanism for forcibly logging out if there is a time that is not used more than a certain amount. Also, on a system that does not allow login with the same account, if two people log in with the same account at the same time, you may forcibly log out the one that was logged in first. Even when forcibly logging out, user should be able to resume input without losing the information user is inputting by reauthentication.

Principle Operable User interface components and navigation must be operable.
Guideline Enough Time Provide users enough time to read and use content.
Criterion Re-authenticating
(2.2.5 AAA)
If the authenticated session expires, the user can continue the operation without losing data even after re-authentication.

URL of Techniques for WCAG 2.0