UPDATE: interface scaling is now supported, starting at 1.4.12 and 1.0.16.

This affects Windows users only. While there is not a permanent fix, the workaround is to override the DPI settings for Maya.

1. Go to your maya.exe file (located somewhere in <Program Files/Maya version/bin>, right click and open up its properties.

2. Go to compatibility tab. Click on Change high DPI settings.

3. Edit the settings as shown below:

Further information about this issue:

• https://forums.autodesk.com/t5/maya-programming/qt-widgets-and-high-dpi-on-4k-monitor-windows/m-p/8567339?fbclid=IwAR1C4uMgtetDDueqHksG97BtOrMUd15R42-lwxCMnBCNwjpZJ-6UeJmyUsE#M9405
• https://forums.autodesk.com/t5/maya-programming/maya-2018-qt-tooling-4k-support/td-p/8567322?fbclid=IwAR0_dAxihHGv5-AXrQMXPFilJQosTuCkJ6ZMKRAeyQTKN49D8L5DV8FDRDA
• https://forums.autodesk.com/t5/maya-forum/maya-interface-scalling-issue-4k-display/td-p/7603510