gmawby, the packages that appear in distros like OpenSUSE are not made by the folks here. Some time after a release here, someone from OpneSUSE will grab the code and build the package as they see it needs to be built. So, people here, unless they have struck the same problem will not generally be able to help you with packaging problems.
I don't use OpenSUSE so really don't know how many changes they make. Debian, for example, make quite a lot of changes and the build process and where things end up is somewhat unrecognizable to the official developers.
I strongly suggest that you use the official FPC/Lazarus packages, there are RPMs available and there will be a lot more help readily available when things go wrong. Carefully remove all the OpenSUSE packages and install from, probably,
https://sourceforge.net/projects/lazarus/files/Lazarus%20Linux%20x86_64%20RPM/Lazarus%202.2.4/Otherwise, if you wish to keep the OpenSUSE, I suggest you read up on fppkg, there should be a man page and it should document how its installed. The same with the RTL, you most definitely need it. Its possible that OpenSUSE break the overall FPC down into individual small packages and you need to install them all. Its a confusing approach but popular with distro package managers.
Davo