Content Credentials cannot be applied to some images on my account

I’m experiencing an issue with the Apply feature in Adobe Content Authenticity (Beta).

Some images can be successfully signed, but some cannot. The most important detail is that the exact same image can be successfully signed using another personal Adobe account, but fails when I try to sign it using my account.

I have checked the following:

• My account is a personal Adobe account.
• It is not an Enterprise, Government, Education, or organization-managed account.
• The files are JPG/PNG, under 20MB, RGB, and above 256×256 px.
• I can access Preferences, Apply, and Inspect.

Could you please investigate whether this is an account-level issue, permission issue, or service-side bug?

I can provide the affected image and screenshots of the error if needed.