BUG #16043: Duplicate Entry Key Message on postgres

The following bug has been logged on the website:

Bug reference:      16043
Logged by:          Jason John
Email address:      komal.sookee@spoonconsulting.com
PostgreSQL version: 11.0
Operating system:   Centos 7
Description:

We are currently experiencing a problem with DataSet objects that behave
differently between Oracle and Postgres.

When we perform "Next Page" / "Previous Page" repeatedly the application
crashes with a "Duplicate Entry Key" Message on postgres.

At the following address
http://docwiki.embarcadero.com/RADStudio/Rio/en/Browsing_Tables_(FireDAC)
(See: Avoiding "Unique Key Violation" Error in LDW Mode at the end of the
page), it seems that our difficulties can come from character encoding
problem. Is there any solution?