I work in the Robotics industry. While the algorithm for our path planning would be a trade secret, how path planning is pursued is not. It's a fundamental concept in robotics. To extend the metaphor, it would be as if my company thought that any robotics work that involved path planning would violate their IP, because I did path planning work with them. It's nuanced to be sure, but some companies are very aggressive as to prevent you from having mobility in your career. Sometimes in a genuine effort to protect their IP, but also sometimes to reduce your negotiating power or punish you.