I went looking for help on this myself and found this thread. It didn't help but I later figured it out.
I had an iphone 6s, fresh OS install (totally wiped) and the latest software as of 1.9.18 and I was having this problem with the phone app.
I went to contacts in the settings app.
turned off all the siri stuff, find contacts in other apps, and show app, then set the default account to my GMail instead of "from my mac" and everything started working correctly. I don't know which specific setting did it but it's working now.
good luck.