Steps to reproduce:
1. Create a new project
2. Create a new Scene and add new UI Button
3. Build scene for UWP
4. Open Windows Display Settings
5. Make sure that Application/Text/Icon scale is set to other than '100%'
6. Open VS solution
7. Build & deploy on local machine
8. Hover over UI Button

Expected behavior: Button is highlighted
Actual behavior: Button isn't highlighted - to actually hit that Button you have to hover mouse far below it depending on App scale (video attached)

Reproducible with: 5.6.0f3-MRTP7, 5.6.2p4-MRTP14
Not reproducible with: 2017.2.0b7, 2017.3.0a4