zapf dingbat font for our report cards doesn't show up correctly on iOS.

We have created new report cards for k-5 and we are using zapf dingbats as a font to create dots, stars and checks. For some reason they are not showing up correctly on an iOS device. They also don't show up correctly on the default pdf viewer on a mac. Without adobe reader installed, the font won't show up at all on iOS or a mac. On iOS with adobe reader, the font still doesn't show correctly.