Attempts to sync offline edits in Collector for ArcGIS on Windows, Android, and iOS devices return the following error message:
Error: An error occurred while synchronizing edits. Service = <URL>: Unable to synchronize replica., Importing delta data changes failed.
The error occurs when multiple hosted feature layers published from ArcMap or ArcGIS Pro point to the same data source. When publishing hosted feature layers with multiple feature layers referencing the same data source, only one table is created in ArcGIS Online. ArcGIS Online does not duplicate tables from the multiple feature layers. Therefore, it is not possible to sync offline edits in Collector for ArcGIS.
To resolve this issue, follow the instructions described below.