[Accessibility] PropertyGrid breaks Tab navigation cycle and causes some controls to be skipped after first traversal

[Olina-Zhang]

.NET version

11.0.100-preview.3.26175.115

Did it work in .NET Framework?

Yes

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

It works in .NET 8/9, regression from .NET 10

Issue description

When a PropertyGrid is present on a WinForms form, keyboard Tab navigation works correctly during the first traversal but becomes inconsistent in subsequent cycles. Some controls are skipped, indicating a regression in focus handling behavior introduced by PropertyGrid because of removing PropertyGrid without this issue.

• First Tab cycle: all controls are reachable ✔

• Second and subsequent cycles:

Some controls (e.g., ComboBox, one Button) are skipped ❌
Focus repeatedly lands on PropertyGrid and a subset of controls ❌

PropertyGridIssue.mp4

Steps to reproduce

1. Create a WinForms (.NET 11 or 10) application
2. Add several controls to the form:

Two Button controls
One ComboBox
One PropertyGrid

3. Ensure all controls have TabStop = true and proper TabIndex order
4. Run the application
5. Press Tab repeatedly to navigate through controls

[LeafShi1]

This issue was introduced by PR #13034