Your code looks absolutely OK. I have no idea why it requires doubleclick to load.

For testing purposes, try adding some debug triggers in the reloadData function. I.e.:

function reloadData(a)
        {           
        console.log('reloadData triggered');
        document.getElementById('ammap').reloadData(a); 
        }

Open browser console. Let's see if the function is being called after first click.

Also, please note that map needs to be fully initialized before it can accept API calls. Are you sure you're not trying to click those buttons while the map is still building itself?