After setting up the latest build of the Codebook app on MacOS and IOS and setting sync to Google Drive, I started getting duplicates, in this case 3 for the 3 devices I had Codebook installed on. I finally resolved by forcing overwrites on 2 of the 3 devices. My iphone then stopped getting changes when I kicked off a sync. I forced an overwrite from device to repository and this resolved it.
My concerns with these issues is that had I started my migration from Wallet and after a lot of work, had to overwrite my work… I’d be grumpy. I couldn’t find any references here on duplicates, which wasn’t wonderful.