Cubase 11 for Windows introduces per-monitor DPI-awareness and scaling according to the scaling factor defined in Window's display settings.
The application is DPI-aware and automatically rescales across monitors having different resolutions.

Some plug-ins, especially VST2 and older builds, might not support HiDPI.
Therefore, an option to resize the plug-in window has been added to the plug-in toolbar:

This option scales the plug-in so that the size looks correct on high resolution displays (e.g. 4K).

Troubleshooting

Before you start troubleshooting, please make sure that you have the latest plug-in version installed. An update might bring DPI-awareness and solve possible issues already. In case of doubt, please contact the vendor of the plug-in. 

Graphical issues

There are known issues with some plug-ins using OpenGL or explicitly ignoring rescaling from the host. Window rescaling in Cubase cannot fix this.

The outcome of enabling 'Allow Window to be resized' on these plug-ins will be a frame of the correct size, with the plug-in UI looking tiny in a corner of the frame and the remaining portion of the VST window being blank (usually black).

Audio issues

In case a DPI-unaware plug-in produces noise or remains completely silent after 'Allow Window to be resized' is being enabled or disabled, please reload the plug-in in the Sends or Insert slot. If this does not solve the problem, please restart Cubase. 

General options and workarounds

• Use the generic plug-in editor: Right-click on the plug-in toolbar ▸ Switch to Generic Editor
• Switch off HiDPI mode in Cubase's Preferences ▸ General.
• Use the plug-in without enabling window resizing and live with the tiny size.
• Use the plug-in on a secondary HD monitor, if available.