FIXED (quick workaround):
To make your missing mouse pointer appear on your Mac while using the Teamviewer app remotely, enable the Mac's Application Switcher by pressing the CMD (?) + TAB (?). This is an easy way to "force" the mouse icon to change from an arrow to a hand pointer, and in doing so, also forces Teamviewer to make the pointer appear on your iPad or iPhone screen as a result of it's change in appearance. Once you've successfully opened the application switcher (and made your mouse appear), you can click away from it (or better yet, actually use it) and still retain the pointer.
Teamviewer places the TAB (?) and Command (?) keys on the upper band of the screen when accessing the keyboard. I've found that you don't actually have to press them together (as you do in person without the app), rather just touch the CMD key first, then the TAB key, and the switcher should come up.