BUG #18406: Connection issue after upgrading to postgres16

The following bug has been logged on the website:

Bug reference:      18406
Logged by:          RAJEEV RAPARTHI
Email address:      rajeev.raparthi@gmail.com
PostgreSQL version: 16.0
Operating system:   Linux
Description:

Hi Team , 

We recently upgraded our postgres version from 11 to 16 , and we are
encountering the connection issue after migration sporadically . 
        DriverManagerDataSource dataSource = new
DriverManagerDataSource(getUrl(), username, getDbPassword());
        dataSource.setDriverClassName("org.postgresql.Driver");

We are observing the issue as "Caused by:
org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC
Connection [The connection attempt failed.] [n/a]"

We are using db3.t3.small machine which has 2GB of RAM .