IE11 SharePoint 2010 lookup drop down menu cannot be selected

Hi team,

I'm using SharePoint 2010, and i create a list with three lookup column, two of them has selection less than 3, i can select the lookup value as i want.

but the third lookup column contain about 50 columns, in the newForm page, the drop down cannot be selected.

this doesn't happen to IE8, so this should be an IE compatibility issue.

I searched and found that I need to add the following to system.webServer section in web.config, but it doesn't work.

   <httpProtocol>
      <customHeaders>
       <!-- <add name="X-UA-Compatible" value="IE=EmulateIE10" /> 
       -->
        <add name="X-UA-Compatible" value="IE=edge"/>
      </customHeaders>
    </httpProtocol>

Please help.