The border-radius is a CSS3 property and it is not available in CSS2. The Advanced PDF/HTML Templates only allow for CSS2 properties to be embedded at the moment, so any CSS3 property (including border-radius) will not be reflected in the printout. so use Corner Radius
<div style=”width: 150px; height: 150 px; corner-radius: 80px; border: 1px solid black; position: relative;”></div>