FontStyle.Bold Not Visually Applied to LinkLabel at Runtime via Code

[Olina-Zhang]

.NET version

10.0.100-preview.7.25351.106

Did it work in .NET Framework?

Yes

Did it work in any of the earlier releases of .NET Core or .NET 5+?

Work in .NET 6, regression from .NET 7 to the latest .NET 10

Issue description

When changing a LinkLabel control's font to bold programmatically at runtime using FontStyle.Bold, the change is not visually reflected in the UI. This occurs even though the Font object reports Bold = true in the debugger.

.NET 7 to .NET 10:

.NET 6:

Steps to reproduce

1. Use a LinkLabel with the default Microsoft Segoe UI font
2. At runtime, execute:
   linkLabel1.Font = new Font(linkLabel1.Font, FontStyle.Bold);
3. Observe font style for linkLabel

WinFormsApp73.zip

Expected Behavior:
Text in the LinkLabel should appear bold after setting FontStyle.Bold via code at runtime.

Actual Behavior:
The text continues to appear in regular style, despite the Font.Bold property being true.