Issue Connecting EC2 Instance to RDS Instance via Management Console

I am currently facing an issue while trying to connect an EC2 instance to an RDS instance via the Management Console.

Here are the details of the setup:

EC2 Instance: The EC2 instance is located in the public subnet and has a public IP. Its security group allows outbound access to the RDS endpoint on port 3306.

RDS Instance: The RDS instance is in a private subnet within the same VPC as the EC2 instance. The necessary security group rules are configured to allow inbound access from the EC2 instance's security group on port 3306.

Connectivity Test: I have successfully tested the connectivity from the EC2 instance to the RDS endpoint using SQL port 3306, and it passed without any issues.

Despite these configurations, when I attempt to connect the EC2 instance to the RDS instance via the Management Console (Action -> Networking -> Connect to RDS instance), I encounter an error stating "The EC2 Instance cannot be found."

I have double-checked the VPC settings, security group rules, and NACL configurations, and everything appears to be in order. However, the error persists. I would greatly appreciate it if you could spare some time to assist me in resolving this issue. Please find the attached screenshot of the error message for your reference.