I wanted to mention this, but it does not effect my work at all - so no urgency whatsoever (for me).
If I hide a grid, populate it from a service, and then show the grid, only 1 row is displayed - i.e. the grid shows only the single populated row set via the UI.
The commands used were:
Appery( "GridName" ).hide();
Appery( "GridName" ).show();