Hi,
It happens, because the same search shortcode is two times on the same page, and the results shortcode is moved there for both search instances. The first search is hidden within the menu, I am not sure what is that for.
You can either try removing that shortcode from the menu, or you can try this custom CSS to get rid off the duplication, if that is not possible:
.asp_sb_1_1,
.asp_s_1_1,
.asp_r_1_1 {
display: none !important;
}