Unable to open in explorer after setting alternate mapping

Hi all,

I'm using a SharePoint 2013 instance in Azure for developing purposes.

I was using links to the style libraries to edit css, js like \\winsrv2012\wwwdavroot\style library\css\myscc.css, it was working fine. I had to configure alternate mapping to be able to access SP from the web and since that change, I can't access the files with the windows explorer anymore.

I'm going to the style library with the SharePoint "Site content" menu and then click on "Open in explorer" button, I get a credential prompt, and even with the right credentials, it's not going through.

I can however edit the files with SharePoint Designer but it not my editor of choice.

If I reverse my settings, deleting the alternate mappings, it's working again, so I know it's not a problem with the web client or wrong credentials.

Anyone have a clue?

Thanks

Michel