Hey mainer56,
Thanks for the reply and additional information, we appreciate it!
When you first create a contact and select Link Contacts, it's only going to give you choices to add a link, not the red (-) minus sign, as there isn't a linked contact yet.
The steps we provided were to try on one of the contacts which already has a Linked Contact, that you were referring to in your original message. Have you had a chance to try with one of those existing contacts? Don't forget to tap on "Edit" up in the top right corner of the contact's page.
If it's still not looking as expected, restart your iPhone and try again. Restart your iPhone
Thanks!