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I understand from your post that contacts on your MacBook are showing as just numbers without any names. If you are using iCloud on both your iPhone and your MacBook, yes, making a change to a contact on one device will be reflected on the other device. In a situation like this first check to make sure all your contacts are listed correctly on iCloud.com . If they are, turning iCloud contacts off and then on again may help refresh the contacts so you would not have to go in manually to add a name to each contact.
The following article also has some information which may be helpful in resolving this type of issue: Get help using iCloud Contacts, Calendars, or Reminders - Apple Support
Let us know how it goes.