3485115 - Intermittent Failure of Cloud Application due to "There is no SAP Cloud Connector (SCC) connected to your subaccount matching the requested tunnel for subaccount..."

The Cloud Application intermittently fails with the following error:

503 Service Unavailable
There is no SAP Cloud Connector (SCC) connected to your subaccount matching the requested tunnel for subaccount <Subaccount ID> and SCC location ID <Location ID>. Please verify the configuration on both the SCC and cloud side.

The ljs_trace.log (for SCC version<2.17) or the scc_core.trc (for SCC version>=2.17) logs may display the following entries:

2024-06-18 20:20:57,417 +0900#INFO#com.sap.core.connectivity.tunnel.core.impl.context.TunnelRegistryImpl#notification-client-4-1#          #Unregistered tunnel channel [id: 0x0c9b7e2c, L:/XX.XX.XX.XX:49304 ! R:XX.XX.XX.XX:443] for tunnelId account:///...
2024-06-18 20:20:57,417 +0900#DEBUG#com.sap.core.connectivity.tunnel.core.impl.context.TunnelRegistryImpl#notification-client-4-1#          #Closed tunnel with tunnelId account:///...
2024-06-18 20:20:57,417 +0900#INFO#com.sap.core.connectivity.tunnel.client.reconnect.ReconnectScheduler#notification-client-4-1#          #Reconnect attempt #1 to connectivitynotification.cf.jp10.hana.ondemand.com:443 - sleeping for 396 milliseconds
2024-06-18 20:20:57,830 +0900#DEBUG#com.sap.core.connectivity.tunnel.client.AbstractClient#notification-client-4-1#          #Successfully connected channel:...

SAP Cloud Connector.

Cloud to On-premise scenario.

KBA , BC-MID-SCC , SAP Cloud Connector On-Demand/On-Premise Connectivity , Problem