I have a S5, my wife has a iPhone 6, we are both on Verizon. For some reason I don't receive any calls she makes to me. She can text or email just fine - but no voice calls. What gives?
Can you call her? I had a similar issue on AT&T. It had to do with my VOLTE network settings. It should allow you to adjust the settings in the iphone. See if playing around with that will fix the issue.