You might face an issue with your PeerApp where the cache system gets disabled. This article explains how to fix or re-enable a disabled system status.
The problem might occur with the systems with version 7.0.11 or earlier. A permanent fix to this issue was included in version 7.0.13 so it is highly recommended that you get your PeerApp system upgraded.
In order to get your system upgraded, contact PeerApp support and mention a preferred maintenance window if possible. Note that the MW takes around 2-4 hours and during the upgrade, the cache will be unavailable and traffic will be redirected to uplink as per PBR and IPSLA configuration.
The release notes for version 7.0.13 are included below.