This issue does not reproduce with the latest Q2 2026 (2026.2.520) version of the Telerik UI for WinForms.
This is why I will close this item and set its status to "Declined" on our feedback portal. Please upgrade to the latest version to take advantage of the improvements in the RadPropertyGrid component.
If you have any other questions or concerns, please do not hesitate to contact us. Thank you!
Regards,
Nadya | Tech Support Engineer
Progress Telerik