wordpress gutenberg validation error on save function

hey
so i am playing with wordpress gutenberg block dev. and already made some simple one. now i am trying to make a more complicated one of a slider.
everything works untill the save function where i get validation error and a bizzare notice about EndTag which i do not get.
this is my save function , for now i am just trying to save the slides titles. if i console log within the map, i do get what i want.

	save: function( props ) {
    const { slides } = props.attributes; 
    const id = props.attributes.id;
    
    const displaySlides = slides.map((slide) => {
      return (
        <div>
          <span>{slide.title}</span>
        </div>
      )
    });

    return (
      <div>
        {displaySlides}
      </div>
    )
  },

i get 1 – block validation: expected token of type ‘endTag’

and 2- block validation : block valifation failed for …..then the expected and the actual. by the way, in the actual i do get the right result

what am i missing here?