It was “Resolutions”. It wasn’t that they couldn’t beam them back. They are already on the ship. They leave them on an abandoned planetoid to survive on their own with supplies and hopefully the ability to find their own cure. Chakotay uses the supplies to build a bathtub for Janeway. He acts all romantic, combing her hair and massaging her but she ends up more fascinated with a monkey that ends up warning them about a plasma storm.