Linux - dropdown controls on windows cause window to get moved below other windows on the screen

[curvedspace]

Describe the bug

This is on Pop OS 24.04 with Cosmic desktop. If you have a main app window in your Avalonia app and launch a new window, for example a detail window of some record on the main window, then have a control dropdown like a combox box where the dropdown is long enough that it goes outside the new window, if you click on a value that is outside the new window, that new window will go beneath the main app window rather than stay in front of it. Also, the combobox value is not updated. This started happening around the end of 2025 for me, it was working before that.

To Reproduce

1. Open app with a main window
2. Launch a new window from there that shows above the main window
3. Have the new window use a combobox or calendar picker that extends outside the new window boundary
4. Try to select a value that is outside the new window
5. The new window goes behind the main window and the value is not selected

Expected behavior

When you select a new value from a dropdown, it should update the control and keep the window that owns it on top of the main window.

Avalonia version

11.3.11

OS

Linux

Additional context

If I click the highlighted value in this picture, the smaller window will disappear behind the main window.