How to reproduce:
1. Open attached project "PolybrushStaticBug.zip" and scene "TestScene"
2. Open "Tools" -> "Polybrush" -> "Polybrush Window"
3. In Polybrush window, select "push and pull vertex tool" (works with pull/pull, smooth and paint tools)
4. Use the tool on any two static objects in Scene view
5. Enter Play mode and observe Scene/Game views

Expected result: objects stay as they were before entering Play mode
Actual result: all static objects are centered and merged on 0,0,0

Reproducible with: 5.6.6f1, 2017.1.3p3, 2017.2.2p4, 2017.4.2f1, 2018.1.0f1
Not reproducible with: 2018.2.0b2

Fixed in: Version 2018.2.0a1 (008bea5b6776)
Wed, 14 Feb 2018 18:36:59 GMT
Branch: trunk