Greetings MomsyX8,
To help troubleshoot the behavior, test after re-creating the contacts that aren't being called to their mobile number as expected.
You can see how to delete a contact here: Manage and delete contacts on your iPhone, iPad, or iPod touch - Apple Support
"Delete a contact
When you delete a contact, it permanently deletes it from your device. And if you delete a contact from your email account, you also permanently delete the contact from all devices signed into that email account.
Here's how to delete a contact:
- Open Contacts and tap the contact that you want to delete.
- Tap Edit.
- Scroll Down and tap Delete Contact then tap Delete Contact again to confirm."
After the contact is deleted, add it back and see if the issue persists: Add and use contact information on iPhone - Apple Support
Let us know if that helps.
Kind regards.