Movie producers in the 2 countries are trying to regulate the movie industry. As part of the plan, they want to control and moderate the number of actors from each country who feature in the flicks produced in the other. They have formed cartels, and they blacklist and ban any producer or actor who flouts their guidelines. These guidelines include getting a permit of a sort to work on movie sets in the other country. I’m not talking about the legal requirement of a work permit – the producers have their own additional permit. It is protectionism, right? But the producers in either country support it wholly, and even collaborate to enforce these restrictions. I guess if an actor is banned in both countries, they can move to Uganda.