I have a client with NAV 2016 and CRM Online (2016.1) and the in-built integration between NAV and CRM running.
The syncing is working fine except for one thing. The status reason for an order should change from Submitted to Invoiced, when the Sales Order in NAV is invoiced. This was working earlier (CRM Online 2016). The status reason remains in Submitted state.
The client have a ondemand workflow to change the status reason when orders look like they have not been invoiced.
I have a test NAV/CRM integration set up and the syncing of Status/Staus Reason Invoiced/Invoiced work instantaneously here.
I can't find the error/log in NAV but maybe I am just looking the wrong place. (CRM consultant, not NAV...)