Telerik version 2020.1.218.45
dpiAware set true.
ToolWindow AllowTransparency = false.
1.Create the ToolWindow with owner MainWindow on the main monitor with dpi 125.
2. Drag the window onto the second monitor with 100 DPI.
3. I remove the Owner (set null).
Changes the size and position (applies the setting of the monitor DPI)
If you enable the setting dpiAwareness PerMonitor, (after window owner set null) a black square flickers.