BUG #16145: Not able to terminate active session

The following bug has been logged on the website:

Bug reference:      16145
Logged by:          MOHAN KUMAR DORAIRAJ
Email address:      mohankumar.dorairaj@globalfoundries.com
PostgreSQL version: 11.2
Operating system:   Red Hat Enterprise Linux Server release 7.6 (Maipo
Description:

Not able to terminate active session even though used below commands

postgres=# SELECT pg_cancel_backend(16647);
 pg_cancel_backend
-------------------
 t
(1 row)

postgres=# SELECT pg_terminate_backend(16647);
 pg_terminate_backend
----------------------
 t
(1 row)

postgres=#  select pid,application_name FROM pg_stat_activity where
application_name IS  NOT NULL AND state = 'active';
  pid  |    application_name
-------+------------------------
 16647 | PostgreSQL JDBC Driver
 19879 | psql