Jacob: Well, I am testing against CRM data which can be manually entered without a QB sync. I have successfully tested getting customer and entity data, adding phone call event, etc.
Jacob - yes, you can enter data into the CRM tables without syncing but that doesn't mean you're not going to run into trouble in other areas of Method. You'll notice that as soon as you login to a Method account, the very first tab you are taken to as an admin is the QuickBooks tab so that you can establish the sync.
As Dave suggested, please link this Method account to a QB file and then test to make sure the problem still happens.