Steps to repro:

1. Open attached project;
2. In the Project folder go to Assets -> FreeSpeedTrees folder;
3. Select 'Broadleaf_Desktop' model;
5. In the Inspector click on LOD 1;
6. Try to scale it up on LOD 1 by dragging it's left edge with pressed left mouse button;

Actual result:
Nothing happens. LOD 1 is not scaled up. See attached video.

Expected result:
LOD1 should be scaled up by dragging mouse button when it is selected; behaviour should be consistent with LODGroup component.

Workaround is to select LOD 0 and drag its right edge to the left in order to scale up LOD 1.

Notes:
- Reproducible on OSX 10.12.2 and Windows 10;
- Reproducible in 2017.1.0a1, 5.6.0b10, 5.5.2p1, 5.4.3f1;
- Happening only for SpeedTree LOD; not happening for regular LODGroup component;
- Reproducible only for LOD 1; not reproducible for other tree LODs.