Description:
The "Edit Page" functionality in Plasma System Monitor does not work correctly. When deleting a specific item from a customized page and saving the changes, restarting the application reveals that a completely different item was deleted instead of the selected one.

Steps to Reproduce:

1.Open Plasma System Monitor and enter Edit Mode on a page.
2.Select a specific item/sensor widget and delete it.
3.Save the changes and close Plasma System Monitor.
4.Relaunch Plasma System Monitor and check the modified page.

Expected Result:
Only the specific item that was manually selected and deleted should be missing from the page.

Actual Result:
The item selected for deletion is still present, but another unrelated item on the page has been incorrectly deleted instead.