Just ran into a wacky bug...
We have a data model where the ID field "ThisThatID" we configured a ListView with a datasource with "autoSync: true". We can read and delete fine, but when we added an item to the datasource, we noticed that the create call was never made, despite the data source showing the new item added, and it's dirty flag as false. We tried manually calling sync but to no avail.
We tried various things, but nothing seemed to work, so we took a gamble and renamed our model's ID field to simply "ID", and updated the ds config. Then boom - it worked. No changed except renaming our ID field from "ThisThanID" to "ID" in both the DS config and the actual model object.
Using the latest kendo 2017.2.
Sample ds config: