This is very similar to what I was seeing yes.
In my particular case, I never saw the new shapes even when zooming in or out.
To give you an idea of what I’m doing…
I created a basic line shapefile to be displayed on the map.
When loading the shapefile in code I create a spatial index as my files rarely ever have them.
Add the shapefile to the map and load.
I Modify the existing shape file and copy it into my data directory. Because the files I create/modify don’t have an index file associated with them, the older index file is not updated.
When I re-run the program, the code to create the index files still runs, but I don’t know if it actually re-creates it if they already exist.
The modified features in the shape file are not displayed at all.
I did find that if I delete and recreate the index files the new features are displayed.
If I just have to delete the index file and recreated it after adding the new shapefile that’s fine, I just need to know that that is the case.
I’ll see if I can come up with a basic example detailing what I’m doing.