Unexpected RPM conflict on %config(noreplace) files - linux

Question

I'm creating my own RPM using rpmbuild.
My RPM contains config files which should never get overridden, even if the RPM contains a new version of these config files.
To archive this, I tagged these with
%config(noreplace) /opt/mypackage/etc/*
in the spec file.
According to the documentation and this site, a locally modified file will never get overridden in this case which is exactly what I want.
However, when doing the following operations:
Install version 1 of the RPM
Change configuration file etc/myconfig
Update package with version 2 of the RPM
I'm getting a conflict:
$ rpm --prefix ~/rpmroot/ -ih dist/mypackage-1.0.1-1.x86_64.rpm
########################################### [100%]
file /home/user/rpmroot/mypackage/etc/myconfig from install of mypackage-1.0.2-1.x86_64 conflicts with file from package mypackage-1.0.1-1.x86_64
Questions:
How can this conflict be explained? (I'd expect that the new version of the config file would be stored as myconfig.rpmnew and the existing remains untouched)
What I am doing wrong?
UPDATE (additional information)
The output of rpm -qcp dist/mypackage-1.0.1-1.x86_64.rpm is:
/opt/mypackage/etc/config1.xml
/opt/mypackage/etc/config2.xml
/opt/mypackage/etc/run.sh
/opt/mypackage/etc/config3.xml
The complete %files section:
%files
%defattr(0444,root,root)
/opt/mypackage/java/*
#dba
%defattr(0444,root,root)
/opt/mypackage/dba/sql/*
%defattr(0555,root,root)
/opt/mypackage/dba/script/*
#srv
%defattr(0555,root,root)
/opt/mypackage/srv/bin/*
/opt/mypackage/srv/lib/*
#etc
%defattr(0664,root,root)
%config(noreplace) /opt/mypackage/etc/*

Answer 1

If this is actually your issue, you may kick yourself ...
I think this may be just because you are "installing" and not "upgrading"
replace -ih with -Uh
I created a test RPM with similar setup, here are the results:
With -ih as you did
$ sudo rpm --prefix ~/rpmroot/ -ih
/home/nhed/rpmbuild/RPMS/x86_64/ptst-1.1.0-1.x86_64.rpm
##################################### [100%] file /home/nhed/rpmroot/etc/a from install of ptst-1.1.0-1.x86_64 conflicts
with file from package ptst-1.0.0-1.x86_64 file
/home/nhed/rpmroot/etc/b from install of ptst-1.1.0-1.x86_64 conflicts
with file from package ptst-1.0.0-1.x86_64 file
/home/nhed/rpmroot/etc/c from install of ptst-1.1.0-1.x86_64 conflicts
with file from package ptst-1.0.0-1.x86_64
With -Uh
$ sudo rpm --prefix ~/rpmroot/ -Uh
/home/nhed/rpmbuild/RPMS/x86_64/ptst-1.1.0-1.x86_64.rpm
##################################### [100%]
warning: /home/nhed/rpmroot/etc/a created as /home/nhed/rpmroot/etc/a.rpmnew
##################################### [100%]