I have an HTC One M9 running Android 6.0 and HTC Sense 7.0. This morning I went to People (phone contacts) and found that my Google account was no longer synced with People. When I check my sync settings, there is not a 'contacts' option for my Google account. I checked with Play Services and all the Google apps are up to date. I signed out of my account on my phone and logged back in with no change. I restarted my phone with no change. All of my contacts still exist on Google, so I haven't lost any information, just sync options...
Any ideas on what is going on?