OK, I've finally had this occur on my personal machine again after a long absence. I've done some more experimenting to try to identify a possible cause. Here are my findings:
- Currently affecting Monitor 2 which set as Main Monitor. This is the only monitor showing the Taskbar.
- The bar is essentially a blank space that allows the user to click the window behind.
- The size of the bar is fixed regardless of the taskbar size. On my monitor, it appears to be 96 pixels in height, meaning the affected window cannot maximise to larger than 984 pixels in height from the top of the screen.
- Moving the taskbar to the top of the screen does not change the maximum height.
- Maximised applications therefore behave as if the monitor has a 1920 x 984 resolution.
- Applications that DO present the bar are as follows:
- Google Chrome
- Internet Explorer
- Microsoft Edge
- Windows Explorer
- Windows 10 Apps
- Adobe Acrobat / Acrobat Reader DC
- Applications that DO NOT present the bar are as follows:
- Office 2016 apps
- MS Paint
- Google Earth Pro
- AutoCAD
- Aside from the W10 apps, the thing these apps have in common is a full screen mode. Toggling the "full-screen modes" present in these apps usually acts as a temporary fix:
- Google Chrome / Internet Explorer - Toggle Fullscreen (F11). The bar will no longer affect that windowed instance of the app,
however new windows will still be affected.
- Adobe Acrobat - Toggle Fullscreen (Ctrl+L). Activating fullscreen viewer mode again fixes the current window but new windows will again show the bar.
- Windows Explorer - No effect.
- Snapping a window to the side of the screen allows it to use the full height of the monitor (Windows + Left/Right Arrow). This then allows the window to be dragged to fit the full width of the screen creating a dummy fullscreen mode, as the issue only affects
maximised windows.
On this occasion, switching which monitor was my Main Display "fixed" the issue. I am still unsure what the trigger for this behaviour is in the first place, but I have been using RDP to connect to various desktops with various sized monitors. Although the
settings force these to resize to suit my monitor's resolution, I can see how this could be linked.
My current setup is with two identical 1920x1080 monitors set to 100% scaling. I have a discrete graphics card so changing Intel HD Graphics isn't an option.