The Flat Presentation option loses its value in the Requirement List gadget after refresh

Description
In the gadget Requirement List, the Flat Requirement Presentation option loses its value after refresh.

How to reproduce

1. Add a Requirement List gadget to a dashboard,
2. Configure the gadget and save,
3. Open the configuration, and check the option "Flat Requirement Presentation", and save,
4. Refresh the web browser page,
5. Open the gadget configuration and the option "Flat Requirement Presentation" is unchecked.
   

Actual result/Attachments
The option "Flat Requirement Presentation" is unchecked after a web browser refresh.

Expected result
The option "Flat Requirement Presentation" keeps the value that was saved.

Version

• Xray v.6.1.0.