Many features in Essentials & GVH such as Saved Projects, Layer Catalogs, and Workflows reference layers using the layer IDs assigned by ArcGIS Server when the MXD document is published. The default behaviour of ArcGIS Server is to assign layer IDs sequentially. Issues can arise when these services are republished and the layer IDs change when the map author has inserted new layers, renamed existing layers, or changed the order of the layers in the table of contents.
There is a method of configuring your MXD document so that ArcGIS Server will instead preserve the initial Layer ID when the service is republished. Within ArcMap or ArcGIS Pro we can enable the "Allow assignment of unique numeric IDs for sharing web layers" setting for the data frame.
If you author your map using ArcMap version 10.3 or later, refer to Esri's documentation about how to preserve layer IDs here: Set up the map document to preserve layer and table IDs.
If you're using ArcGIS Pro, refer to its documentation here: Set up the map document to preserve layer and table IDs.
Once "Allow assignment of unique numeric IDs for sharing web layers" has been enabled, you will be able to check or change the Layer ID in ArcMap under the General tab in the Layer Properties menu