Whenever I get to the end of a max lair in the crown tundra the legendary at the end disappears somewhere into the den, why can’t I catch them? It doesn’t give me the option to catch them, and at the end of the raid it doesn’t give me the option to pick Pokémon I’ve caught.
It’s because you’ve caught them before
You can’t catch legendaries in dynamax adventures more than once.
Hope this helps!