Un-Marshamellow Your Caller ID on Android 6

So, ever since I made the update to Marshmallow, the caller ID stopped working.
Now, I really don't give much of a fuck about that, mostly because of work I have to answer every call I get on the cell; but the GF - who incidentally updated her Moto G to Marshmallow while on vacation in Miami, it seems that in Argentina that update wasn't available- has a real need for that feature, so, she told me how to fix the problem, and the fix is an amazingly simple one...
You have to simply remove the Gmail account, from Settings > Accounts, and add the account once again.
When all the contacts are downloaded, the caller ID will automagically work once again...