Messaging API 400 Bad Request on Web Channel Config

What is the reason this setting causes a 400 error when updating the web channel via PUT /api/v2/messaging/channels/web/{channelId}?

{
 "enabled": true,
 "name": "Support Portal",
 "routingType": "longLived",
 "settings": {
 "allowAnonymous": false,
 "defaultGreeting": "Hi there"
 }
}

Check your routing type value. The API expects longLived or transient, but if your payload has hidden whitespace or incorrect casing, it throws a 400. Ensure the JSON structure strictly matches the schema definition for web channel settings.