Blocked contacts apparently not syncing across devices

I have two of my five Apple devices with me on my travels - iPhone and MacBook.

Running Catalina 10.15 and iOS13.1.2.

When I block a contact in Mac Mail I get a red hand.

When I block a contact in Mail on my iPhone I get a grey hand.

(In iCloud Mail there is no indication a contact is blocked at all - some consistency would be good!)

Apart from this strange difference in graphics, the blocked contacts don't appear to sync across the two devices.

Should they? Do yours?

Thanks.

P.S. I should add that I'm not talking about contacts in my Contacts book, just general spam mostly.