WebRTC softphone WebSocket disconnects after 30s in AU-1 BYOC

Looking for advice on persistent WebSocket drops for WebRTC softphones in our AU-1 BYOC environment. Terraform applies cleanly, but the client disconnects with error 1006 after exactly 30 seconds. Provider version is 1.68.4.

resource "genesyscloud_telephony_providers_edges_edge" "main" {
 name = "AU-Edge-01"
 description = "Primary BYOC Edge"
 region = "au-1"
 
 webrtc_enabled = true
 
 edge_settings {
 keep_alive_interval = 30
 max_session_duration = 3600
 }
}