Core data with iCloud.. seems like they have two storage

I made app for iOS and Mac with core data with iCloud. Synchronizing with any device is working great until iOS8 came out.

since iOS8 came out, in XCode and provisioning portal, I had to put one more ubiquaty key like "iCloud.xxx.xxx" with my previous one "XMKH8e3SK.xxx.xxx" at the same time. I didn't want to make any change to my app but I had to, because once Apple migrate my apps's data to iCloud drive, data is gone and it's restored when I put that key(iCloud prefix "iCloud.xxx.xx" in XCode and provisionaing portal).

It seems OK after that.

but now I have really serious problem.

my iPad ~ my Macbook Air is syncing each other and my iPhone 6 ~ my iMac is syncing each othere BUT NOT ALL DEVICES!! It's too weird. Can not believe this is happening. I hope not my customers are facing this issue. but They are!

How can i solver this issue?

Thanks.