Bug: "Save As" instance visual override

[HugoBDesigner]

It was hard to come up with a concise title, but here's the gist: in Hammer, when you have an instance within a map, you can click "Edit Instance" to open it, change the map, then use "Save As" to save to a separate file. Then when you close that map and go back to the main one, every instance of the original instance is (purely visually) replaced by the newly saved map, even though the instance's path doesn't change. Clicking "Edit Instance" again opens the newly saved edited file, rather than the original one (even though the file path in the instance object is different). Reloading the map fixes the issue.

A mouthful, I know. Just watch the video:

https://github.com/user-attachments/assets/2d56d4b0-a89e-43ca-9be3-7611dcdce6bd