I've started a career mode with custom settings with one of them being to have to pay an entry cost to unlock a new part once it has been researched. I have researched new parts and I have the required funds to unlock them but I can't seem to unlock them. I assume it's X on the PS4 but it does nothing as if I haven't researched them. It's really annoying as these are the difficulty settings I want to use but I cannot progress any further. I've tried restarting a new career and it keeps happening. Does anyone know if this is a bug or if I'm missing something really obvious?