Facebook logins expire from time to time (password change, security review, or simply age). When that happens the account shows Expired in Accounts, and the assistant + publishing stop for that page until you reconnect.
- Open Accounts.
/accounts
- Find the card with the Expired status.
- Press its reconnect/connect button and log in to Facebook again.
- Approve ALL permissions and pick the same Page.
- The status returns to "Connected" — replies and publishing resume automatically.
Tip: the Account Health page warns you the moment a login expires. /health