Hello,
We just upgrade to online CRM Dynamic 2016. This was not an issue in CRM Dynamic 2015.
The issue is the auto save is reopening “resolved cases” or inactive cases.
The process to close all cases is shown below:

This is how the case looks before closing:

After entering the date into the OCO Investigation Complete field this is what it looks like for a moment.

As you see, the case is now inactive and the case is set to Resolved.
The case will revert to Active after a few moments. Also, if I try to leave the case quickly to avoid the auto save, the case still reopens.
I turn off Auto Save and the cases stay closed.
The odd thing, is my client has a process to close cases before being investigated and this is quite common. Still, the closure process is the same, and the Case Business process flow for closure is the same on both intake closures & complete OCO closures. In this case, it sets the status reason to complete closure (which is what the process should change the status reason to.)
Any suggestions? Any other info you need?