The Test Harness supplied with the library allow each library unit to be compiled and simulated in isolation. When the library unit is instanced within your design, compilation result may differ from the result obtained with the test harness. This may be because compilation of your system may need arguments not present in your system.
Please search the Makefile provided for UUT_TARGET_COMPILE_ARGS. For each library element there may be compile arguments used to avoid errors or to improve performance, e.g. specifying memories to be on separate banks to avoid wait states. These arguments will likely change with each release as the compile tool changes with each release.