WCAG 2.2.5: Re-authenticating
WCAG 2.2.5 Re-authenticating is a level AAA success criterion from WCAG 2.0. When a session expires, the person can re-authenticate and continue without losing data.
Someone who took longer to type an address should not lose the whole form.
How to test
Fill checkout, let the session expire, sign in again. The fields should still be there.
How to fix
Store the form and restore it after login.
Example that fails
Session expiry wipes the shipping address.
Example that passes the check
After login the address is still filled.
Shopify
Do not add a custom checkout that drops data on session refresh. Prefer Shopify Checkout, which keeps the cart.
WooCommerce
Use WooCommerce's session cart so login restores the basket and address.
WordPress
Persist form drafts before requiring login.
Wix
Keep form entries if the member login expires.