Bug: Hammer flashes when undoing/redoing changes of `func_instance`

[darvil82]

Describe the bug

When undoing or redoing the changes of the properties of a func_instance entity (including position), Hammer will flash, which can be quite uncomfortable to watch if the user has to undo plenty of changes.

It looks like Hammer loads the instance map and inmediately switches back to the main map?

To Reproduce

1. Open a map.
2. Create a func_instance and set a map file on it.
3. Modify the entity. Translate it, for example.
4. Undo the changes.
5. Hammer quickly flashes.

Issue Map

Any.

Expected Behavior

The previous behavior. No flashes when undoing changes related to instances.

Operating System

Windows 11

[Obsolete-Wolf]

Same issues with texture browser.