[Windows] DatePicker Format Not Applied as Expected on Windows

[TamilarasanSF4853]

Description

When setting the Format property on a DatePicker control to a standard format string (such as d, D, f, F, g, G, m, M, o, O, r, R, s, u, U, y, Y), the expected date formatting is not applied on the Windows platform. While the property works as intended on other supported platforms (such as Android and iOS), it has no visible effect on Windows.

Android	Windows
Screen.Recording.2025-06-24.at.11.12.41.AM.mov	Screen.Recording.2025-06-24.113347.mp4

Steps to Reproduce

1. Run the attached sample. TestingApp.zip
2. Observe the DatePicker's Format property behavior on both Android and Windows devices.

Link to public reproduction project repository

No response

Version with bug

10.0.0-preview.4

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

Windows

Affected platform versions

No response

Did you find any workaround?

No response

Relevant log output

[similar-issues-ai]

We've found some similar issues:

• Date format DatePicker wrong in Windows #9255 , similarity score: 82%

If any of the above are duplicates, please consider closing this issue out and adding additional context in the original issue.

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This issue has been verified in Visual Studio 17.14.6 Preview 1.0, with .NET MAUI versions 9.0.80 & 9.0.0. It can be reproduced on the Windows platform.

[sheiksyedm]

Related to this #30011