Contacts from iPhone not syncing to my Mac

Take help of a web browser and enter in www.icloud.com with the apple id and password used in an iPhone , the contacts that were saved in will be visible select the desired contacts and click on gear icon in the left bottom corner and click on export as v card .

Open finder , click on downloads , right click on .vcf file and open with contacts .app( default ) .

The address book will get opened , a pop up window will appear stating are you sure you want to add number of cards , click on add .

Again open your address book the contacts that were in the iPhone will be transferred under the section “ All contacts “ in the Mac address book .

Sign out from www.icloud.com used with Apple ID and password for an iPhone .

Then enter in www.icloud.com with the apple id and password used in the Mac , click on gear icon and click on import as v card all the contacts will be transferred in the iCloud server , click on create group on the bottom right corner an untitled folder will be created in the side bar and the contacts from iPhone are transferred to the iCloud server account .

See some articles iCloud: Export a contact as a vCard from iCloud Contacts

iCloud: Import a contact into iCloud Contacts

iCloud: Create a group in iCloud Contacts

Read the steps in this article If your iCloud Contacts, Calendars, or Reminders won’t sync - Apple Support

The All contacts on my Mac means the contacts saved in address book , they can include some contacts from iCloud , some groups created .

It's the choice of administrator to drag few contacts from All on my Mac to other groups or in All iCloud or vice - versa or randomly save any where .

Suppose there are three contacts in All on my Mac , Mr A , Mr B , Mr C , the contacts that saved in iPhone will be common between All iCloud , but not be same as In All on my Mac .

Mr B , Mr C will be in All iCloud of Mac and iPhone , But Mr A not necessarily saved in iPhone .

Note : you have to manually drag and drop contacts , there is no such settings done automatically , the reason behind if a person don't want to share all contacts from his Mac to iPhone or vice versa even its signed in with same Apple ID and password on the same network , they can restrict the particular contacts to be synced .

Apple engineers have designed address book in this way only .

Note : you can transfer contacts from iCloud.com using a web browser to another group , but groups created from iPhone will not sync in iCloud.com or Mac , the contacts from All iCloud  that were saved inside it will sync when iPhone / Mac are signed in with same Apple ID and password on the same network ( the contacts box from Mac / iPad should always be turned as on ) .

if you had created a group " A " in iPhone , that won't sync in iCloud.com you have to manually create the same group with same name " A " in iCloud.com

See the articles Set up and use iCloud Contacts - Apple Support

Create and manage groups of contacts on iCloud.com - Apple Support