Steps to reproduce:
1. Create a new project
2. Open Preferences window
3. Close project
4. Reopen project

Expected results: Preference window minimum scale is 800x600
Actual results: Preference window minimum scale shrinks down to 1x1

Reproduced with: 2019.3.0a8, 2019.2.0b8
Not reproducible with: 2019.2.0a13, 2019.1.9f1
Regression introduced in: 2019.3.0a1, 2019.2.0b14

Note:
Other reproductions steps are:
1. Create a new project
2. Open Preferences window
3. Enter play mode
4. Try scale down the window
These steps do not work all the time