When using a QComboBox with a popup inside a QDialog-based window in a Qt WebAssembly application, the popup does not respond to any mouse inputs. The same widget works correctly when used in the main window.

Steps to Reproduce:

1. Open the attached minimal example project.

1. Build and run it as a WebAssembly target (tested in both single-threaded and multithreaded modes).

1. Open the popup calendar and try to interact with it using the mouse 

Expected Result:
The popup or QComboBox should accept mouse input and allow selecting a value.

Actual Result:
The QComboBox appears but does not respond to any mouse inputs.

Additional Information:

• Issue occurs only in WebAssembly builds.

• Behavior is the same in single-threaded and multithreaded builds.
• Using these widgets in the main window works as expected.