You set up a bastion host in your Virtual Cloud Network (VCN) to allow only your IP ad-dress (140.19.2.140) to establish SSH connections with your…

You set up a bastion host in your Virtual Cloud Network (VCN) to allow only your IP ad-dress (140.19.2.140) to establish SSH connections with your compute instances that are deployed in a private subnet. The compute instances have an attached Network Security Group (NSG) with a Source Type: Network Security Group (NSG), Source NSG: NSG-050504. To secure the bastion host, you add the following ingress rules to its NSG: Type: All TCP Proto-col: TCP Port Range: 22 Source: 140.19.2.140/32 Type: All TCP Protocol: TCP Port Range: 22 Source: NSG-050504 However, when you check the bastion host logs, you discover that there are IP addresses other than your own that can access your bastion host. What is the root cause of this issue?