You may remove a Legacy Contact for your Apple ID as described in How to add a Legacy Contact for your Apple ID - Apple Support
Remove a Legacy Contact
You can remove someone as a Legacy Contact at any time in your Apple ID settings.
+ On your iPhone, iPad, or iPod touch, go to Settings > [your name] > Password & Security.
+ On your Mac, choose Apple menu > System Preferences, then click Apple ID and select Password & Security.
Under Legacy Contact settings, choose the contact’s name to see more options.
Tap or click Remove Contact to remove them as a Legacy Contact. They won’t receive a notification of your decision, but you won't appear in their Legacy Contact list if they have an Apple device that includes this setting. The access key they received when you added them will no longer work.
Did you try restarting your device?
If you still have questions or problems:
Refer to this document for ways to contact Apple ➞ Choose your country or region - Official Apple Support
Select your country (also look for "other" regions), then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.
or:
Contact Apple for support and service by telephone ➞ Contact Apple for support and service - Apple Support