[Bug]: Cannot BindWithValidation on ComboBox.SelectedValue

[Nextra]

Describe the bug 🐞

The new BindWithValidation for WPF (introduced in #3874) is not able to bind to ComboBox.SelectedValue.

Instead, an Exception is thrown:

System.ArgumentException: 'Dependency property not found on Object'

Step to reproduce

1. Clone reproduction repository
2. Start the application

Reproduction repository

https://github.com/Nextra/ReactiveUIBindWithValidationBug

Expected behavior

BindWithValidation should work on ComboBox.SelectedValue

Screenshots 🖼️

No response

IDE

Visual Studio 2022

Operating system

No response

Version

No response

Device

No response

ReactiveUI Version

20.1.63

Additional information ℹ️

No response

[ChrisPulman]

Thank you for raising this, I will try to resolve this as soon as possible. List controls have always been a sticky issue for binding.

[Nextra]

Thank you.

If I might add, the BindWithValidation extension should also have nullable annotations to match the others.