Unable to block contact on iMessage for Mac OS 10.14.2

I am unable to block a contact on my mac's iMessage app (Mac OS 10.14.2).

I go to preferences > imessage > blocked > + , and then a drop down of my contacts appears. I select the name from the list but then the list just disappears and nothing is added to the blocked list. (And yes they are still able to contact me).

Any ideas as to what I'm doing wrong?

Solution 1:

As a workaround, you can add a phone number as blocked in the FaceTime app on macOS, and it will also register as blocked in Messages (at least it worked for me, and I had the same issue on 10.14.3).

Solution 2:

I think the issue here is your contact syncing service trying to override what you're trying to do.

They should be using one account/service like Google or iCloud or Yahoo and not all together as you get this round robin effect of one service overriding what you are trying to do.

(Source)

To stop this you will need to stop syncing more than one account on your Mac.

To stop Yahoo sync:

How do I stop Yahoo Sync?

To stop Google sync see here.

To stop iCloud sync:

Choose Apple menu > System Preferences.

Click iCloud.

Uncheck contacts.

Another issue:

Another issue is the phone can be updated from other devices as they are set to say iCloud but the iPhone is set to "Keep on Phone".

If the issue persists it is probably a bug, you can report it here.