The issue was due to an abusive service. Discord has contacted us back and whitelisted our IPs. All services are now operational.

We have identified the root cause of the issue and we are in contact with Discord to resolve it.

We are currently investigating a sudden increase of rate limits to Discord endpoints, affecting only AppBox services.

This only affects AppBox services trying to use the Discord API for Discord bots. Minecraft and Rage MP services are unaffected by this.