Custom Widget code works ok on Chrome, but not displaying correctly on Safari

Hi all,

I've had some help with this code before, but I've added a code widget with the below code.  This displays ok (not great but ok) with Chrome, but with Safari the Drop down lists for the dates Check in and check out don't display.  Sometimes widget hasn't shown at all.  Does anyone have any insight as to why?

<div id="search-widget_IO312PWQ"><script>!function(e,t,a,n,c,r){function s(t){e.console.log("[Guesty Embedded Widget]:",t)}var i,d,l,o,y,m,g,h,p,u;n&&(i=n,d=t.getElementsByTagName("head")[0],(l=t.createElement("link")).rel="stylesheet",l.type="text/css",l.href=i,l.media="all",d.appendChild(l)),o=function(){try{e[a].create(r).catch(function(e){s(e.message)})}catch(e){s(e.message)}},h=!1,y=c,m=function(){h||this.readyState&&"complete"!=this.readyState||(h=!0,o())},(g=t.createElement("script")).type="text/javascript",g.src=y,g.async="true",g.onload=g.onreadystatechange=m,p=g,(u=t.getElementsByTagName("script")[0]).parentNode.insertBefore(p,u)}(window,document,"GuestySearchBarWidget","https://s3.amazonaws.com/guesty-frontend-production/search-bar-production.css","https://s3.amazonaws.com/guesty-frontend-production/search-bar-production.js",{"siteUrl":"airpeaceofmind.guestybookings.com","color": "#ed87c6"});</script></div>

the website in question is currently apom.squarespace.com password test

Many thanks