This counts Packet-of-Disconnect failure notifications sent for one specific user group, reporting disconnects that could not be carried out for members of that group. A rising count isolated to one group points to a group-specific problem, such as stale session identifiers used by whatever job triggers disconnects for that particular tier, rather than a gateway-wide RADIUS issue. If only the 'trial-30day' group shows rising failures while other groups show none, the fault lies in how that group's expiry job references sessions, not in the gateway's POD handling generally.