PIE registers 2 Default Brushes in the blank level

PIE registers 2 Default Brushes in the blank level. It's expected behavior to have 1 Default Brush, which is the case in other play modes, but PIE registers 2.

Licensee Description:

This is an issue for our game because I am using an Actor's index in the level's Actor list (ULevel::Actors) to create initial seeds for random number generators (with FRandomStream), to ensure that the level plays deterministically every time it's played, but to ensure that each actor of the same class generates different random numbers. My assumption was that the level's actor list would always initialise the same way, as it's essentially created by the level designer. Apparently this isn't the case.

1. Open the attached test project
2. Play-In-Stand alone (1 Default Brush will be registered)
3. Exit
4. PIE

Results: PIE registers 2 Default Brushes in the blank level

Expected: For only 1 Default Brush to be registered in any playmode