problem drop-down

I have a problem, I add a drop-down menu and I don’t know why but it shows 2 fields, the normal drop-down with the options that I put and an additional one as search but I don’t know why I disable the search so that only the options drop-down is seen , this is how https://prnt.sc/ula5ec looks and this is the page (https://capacitaciones-mintic.com/register/) I need urgent help

The page I need help with: [log in to see the link]