JimW,
I have the same issues in a brand new 2017 file. If I open up a new file draw and arc or use the callout tool with an arc and an arrow end, they do not appear. Sometimes when scrolling in and out you can see them ghost. I have tried clicking on and off the arrow head in the object info pallet, changing the arrow head, etc. Sometimes it will appear and then go away when I scroll. Sometimes it will appear in the design layer, but not in the viewport or when I export a PDF. There is no constancy. The attached image shows the callout tool i the design layer in brand new file in 2017 on the left and the exported PDF on the right. You can see the callout looses it's arrow heads when exported.
Any other form of the callout tool seems to work fine.