Admin & logged in user carts aren’t being cleared because WooCommerce handles admin and logged in user carts differently. If you run a members only WooCommerce store, you might want to clear those carts as well.
We’ve built a feature that lets you do exactly that, it’s called Force Admin & Logged in users.
Force Admin & Logged in users can be found at the Clear Cart > General Tab. Clicking the checkbox will active the feature that clears all admin carts & logged in user carts at the same time as your modified expiration time.
The Force Admin & Logged in users doesn’t currently check for activity, and therefore will clear the sessions/carts as soon as the expiration time has passed.