Steps to reproduce :

- use an external monitor with the native resolution of 1280x1024, 4:3 format
- set the primary monitor's resolution to 1600x900
- open Unity and arrange the layout as following : scene and game tab on the external monitor, hierarchy project browser and inspector on the primary monitor
- maximize the scene tab on the external monitor
- reimport an asset or restart Unity and notice that the scene tab has not maintained its dimension