IoT Hub having more Ingress capacity than the Throughput unit defined in its Event Hub

Hello everyone,

I am working with Azure IoT Hub. As IoT Hub is built on top of Event Hub and inherits its properties hence if I am using the Standard tier of Event Hub with a 1 Throughput unit I should be having an Ingress of 1MB/sec and Egress of 2MB/sec according to https://learn.microsoft.com/en-us/azure/event-hubs/event-hubs-scalability#throughput-units . In short my IoT Hub(with Event Hub of 1 Throughput unit capacity) should have the capability to Ingress 1MB/sec and Egress 2MB/sec.

I have also tried to send 5MB/sec of data to my IoT Hub and it works fine however it should be giving https://learn.microsoft.com/en-us/dotnet/api/microsoft.azure.eventhubs.serverbusyexception?view=azure-dotnet  exception since it has Ingress of 1MB/sec.

All answers appreciated.