iMac book contacts are not syncing with iCloud

I have studied a lot of these posts. Many people are kind enough to list steps. I've had two advisors online today and will have to speak to a "Senior Advisor."

Suddenly Contacts on my iMac are not syncing with my iPhone or my iPad. However, I tried to enter a new contact on my iPhone, and it synced with iCloud. Cannot figure out why the iPhone synced with the iCloud, but my iMac and my iPad won't.

All are updated, all are using the same email/password. I have turned off both the iPad and iPhone and "waited" 5 minutes and then restarted them. No changes. I'm at a loss. Anyone?

#Contacts #Syncingissues