Ha, I see now. lazreportpdfexport is a separate package.
Yes, it is a bit complicated.
Lazreport you can install form the IDE, same as the exporter but the exporter relies on powerpdf which can be installed using OPM.
Could this be a mode or compiler setting issue?
Could be a define is missing indeed or overused. At the top of pdftypes it reads:
{$IFDEF LAZ_POWERPDF}
{$MODE OBJFPC}{$H+}
{$ENDIF}
.. and which could then cause the issue.
The original bugreport mentions something about different compiler modes and circumventing issues with packset.
tbh, I have no idea how to test that...