Setting a parent and child static mesh scale to negative effects the rotation on child when Snapped To Floor

Setting a parent and child static mesh scale to negative effects the rotation on child when Snapped To Floor

Looks to be directly related to this JIRA:

https://jira.ol.epicgames.net/browse/UE-31521

From test project:

1. Open the attached test project
2. Select the SM_BoxText2 (diagonal box)
3. Press the End-key to snap it to the floor

Results: The Z-Rotation value with flip between a positive and a negative value when the static mesh is snapped to the floor

Expected: For the rotation value to stay the same

From Blank project:

1. Open a new blank project
2. Import the attached test fbx
3. Drag an static mesh into the level
4. In the Details panel, set the Scale to 1.0, 1.0, 1.0 <--- note the Y field is minus one
5. Drag another static mesh into the level & make it a child of the first one
6. Set it's Scale to 1.0, 1.0, 1.0 <--- note the X field is minus one
7. Set it's Rotation to 0, 0, 110
8. Save all
9. Select the child static mesh and move it off the ground several units
10. Press the End-key to snap it to the floor