Play Prompt block drops with SIP 503 during Edge 2024.6.1 local survivability on R750

Primary WAN cuts again during the Tokyo ISP window and the Edge 2024.6.1 pair flips straight to local survivability. Architect flows using the Play Prompt block just drop calls with a SIP 503 after 30 seconds. Disk’s got plenty of room and the media cache isn’t full.