UI content doesn't display correctly on secondary displays using Custom UI scaling

Steps to reproduce:

1. Setup a Multi-Display environment with the following parameters
   1. Primary display: 150% scaling
   2. Secondary display: 100% scaling
2. Change UI scaling in Editor -> Preferences -> UI Scaling to these values
   1. Uncheck "Use desktop scaling"
   2. Set "Use custom scaling value" to 100%
3. Launch the Editor with any project on the primary display
4. Open any secondary window, e.g. Preferences
5. Drag this window to the secondary display

Actual results: Window content doesn't fill in the entire window frame and appears "cut off" on the side

Expected results: Window content fills out the entire window

Reproducible with versions: 6000.4.0b2, 6000.5.0a1

Not reproducible with versions: 6000.3.2f1

Tested on (OS): Windows only issue

Notes:

• It seems all secondary window have this issue but only with this specific DPI scaling setup