The only reason come out like that , after install Office 365, you find out is office 2016. But instead use KMS Office 365 to activate, you choose use Office 2016 KMS activation method to activate.
Now become two Office Program in your PC. This will only come all kind of error.
Control panel , uninstall all Office Program
Choose to install Office 365 or office 2016 standalone program, but not both.
Office 365 installation finish, will show office 2016. Use Office 365 KMS batch file run by admin right online.
Activation will done.
It will become Office 365 base Office Office 2016. It still can have future feature update if you use Windows 8.1 or under. Or can upgrade to office 2019 (for Windows 10 only)