An L3 Support Engineer is troubleshooting a severe performance degradation and partial VM unavailability in a VCF Workload Domain configured with a vSAN Stretched Cluster. The cluster utilizes the "Witness Traffic Separation" (WTS) feature.
The engineer pulls the vmkernel.log from host-sec-01 in the Secondary fault domain:
```
2026-05-12T14:15:22.456Z INFO vsanmgmt - Entering Stretched Cluster Health Check
2026-05-12T14:15:30.112Z WARN vsan-network [vmk2:vSAN-Data] Failed to ping Preferred-Gateway:
Destination unreachable
2026-05-12T14:15:35.889Z INFO vsan-network [vmk3:Witness-Traffic] Ping to Witness-Appliance (10.50.1.10) Successful
2026-05-12T14:15:36.001Z ERROR cmmds - Cluster partition detected. Secondary site isolated from Preferred site.
2026-05-12T14:15:38.220Z INFO clom - Object 5543505c-xxxx entering DEGRADED state.
2026-05-12T14:15:40.500Z WARN vsan-network [vmk2:vSAN-Data] High congestion detected on ISL.
TxQueue=100%
2026-05-12T14:15:45.000Z ERROR vobd - [vSAN] Node uuid-sec-01 has lost communication with Witness node uuid-wit-01 via WTS network.
2026-05-12T14:15:45.500Z ERROR cmmds - Component state for Object 5543505c changed to INACCESSIBLE.
```
Based on the logs and the integration between Fault Domains and Witness Traffic Separation, which of the following statements explain the root cause and system behavior? (Select all that apply.)