How to reproduce:
1. Open the user's attached "PolygonCollider2D_RemovedShapes_2019.4.9.zip" project
2. Open the "SampleScene" Scene
3. Enter Play Mode
4. Press the "Pause" button after entering Play Mode
5. Press the "Step" button until the balls touch the PolygonCollider2D shapes (See "1274172_repro.mp4")

Expected result: Both ball GameObjects hit the PolygonCollider2D shape without going through
Actual result: The left ball GameObject goes through the PolygonCollider2D shape's top vertex (Part of the PolygonCollider2D shape is getting removed)

Reproducible with: 2019.4.10f1, 2020.1.5f1, 2020.2.0b2
Could not test with: 2018.4.27f1 (The PolygonCollider2D shape is not visible when downgrading the project)

Note:
- The issue is not reproducible if the PolygonCollider2D Component's Offset property is slightly increased (Now it's 0 on both X and Y axis)