Hi and welcome, Willow. They look just like my Peruvian daffodils to me.
Peruvian Daffodil (Ismene x deflexa)
Their foliage does look exactly like amaryllis foliage so if there were some planted in the same area where you put your amaryllis, that may have caused the mixed blooms. Here are a couple of pictures of my plants. Their foliage does die back in winter, too.
