I have Azure Databricks premium subscription. I am running the Python interactive Notebooks in the Databricks Wokrspace using Serverless compute since the last few days. Today I received an alter in my email saying the monthly Billing already crossed the set threshold value. I check the cost by services and found out the NAT Gateway service had significantly increased the cost. PFA the screenshot. 

Why is Azure invoking the NAT Gateway and how can I cut it off entirely?