If your Windows scaling is above 100% and you close the editor while it is maximized, the next time you open it the editor window will state that it is maximized even though it isn't. You have to restore it down and maximize it again to get it to actually maximize.

1. Make sure your Windows scaling is above 100% (tested against 125%)
2. Install Unity
3. Create a new project with any settings
4. When the project is open, maximize the editor window
5. Close Unity
6. Open Unity again and load the previous project

Expected Result:
When the editor loads, it should start properly maximized.

Actual Result:
When the editor window loads, it is not maximized even though it states it is.

Tested on Windows.

Looks like a regression in 2019.1.0a9.

Occurs on:
2019.1.0a9

Does not occur on:
2019.1.0a8, 2018.3.0b11