In #8473 I introduced a component specific renderfield override so that layouts can be "free" of static form / field rendering code blocks. As mentioned in the description and discussion, the implementation is not very clean. Parsing HTML is seldom a good idea.
Testing Instructions
To check that the reported problem has been fixed:
Create a contact item in the backend
Create a menu item for that contact
Enable the "Captcha - ReCaptcha" plugin and select that plugin in the site tab of the global configuration Note: You may have to generate a key to be able to use / see the captcha on your webseite. Any key that is valid for a website is also valid on localhost.
Open the contact page in the frontend. As reported, the captcha field shows the (optional) suffix, which should not be there
@Test working fine. Thanks :)