Form to be signed only by certain Signature Certificates and Automatically lock the form after singing

[Bassel]

Hello,

I have a form that I would like to restrict singing it to certain certificates.

I tried to check the box under Signature Settings/Signing certificates/Specify the Signing Certificates.

every time I check the box and then OK I come back to the setting and  I see the check box unchecked

and then I was able to sign the document with different certificate after the distribution.

could you elaborate me how to solve the issue

Thanks