@Nakashimafied The feature wasn't broken at first, and I haven't read anything saying it was broken in a later patch, although that's possible. And yes, I was suggesting using MasterController, either choosing the job and level manually or perhaps reassigning the career opportunity if it's available. (I'd have to check whether that works; I'm not sure whether it works as an opportunity or is a separate mechanism.)
Since you use MC, do you also use NRaas StoryProgression? One thing that occurred to me is that if you have Allow Find Job set to False for this sim, SP may have blocked the career change. You can see the options by clicking on the sim and selecting NRaas > SP > Sim Options > Career: Allow Find Job. A setting of (True) or (False), in parentheses, means that the option is coming from an upstream setting, probably Caste or Town Options; if the setting says True or False and is not in parentheses, you've set it explicitly on the sim.