From OpenPlant Update 9 release, a new feature has been released for the handling of design data in PlantSight to be used with OpenPlant Modeler CE.
In OpenPlant Modeler, a new tool Sync to iTwin has been added in the collaborate ribbon. This tool is used to synchronize changes made in a DGN to an iTwin on the iModelHub.
Usually, when changes are done to the design file in the Plantsight connected project. The check-in option simply moves all the data/components to the plantsight which can be visualized. Also, the same data can not be seen in the active dgn file as this is pushed to plantsight. Sync to iTwin option allows this data/Components to pushed in the Plantsight & can be seen in the active dgn. This wiki article, explains the procedure how to enable & use this tool.
If above problem still persists, then please create a Service Request and contact the Bentley Product Advantage group. Please include a list of all relevant details to get in depth analysis for a solution or workaround