SwiftData with CloudKit Sync Issue

Question

Created Dec ’25

Replies 2

Boosts 1

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I am using SwiftData with CloudKit to synchronize data across multiple devices, and I have encountered an issue: occasionally, abnormal sync behavior occurs between two devices (it does not happen 100% of the time—only some users have reported this problem). It seems as if synchronization between the two devices completely stops; no matter what operations are performed on one end, the other end shows no response.

After investigating, I suspect the issue might be caused by both devices simultaneously modifying the same field, which could lead to CloudKit's logic being unable to handle such conflicts and causing the sync to stall. Are there any methods to avoid or resolve this situation?

Of course, I’m not entirely sure if this is the root cause. Has anyone encountered a similar issue?

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Answer 1

schultzapps OP

1w

This might be late but I'm currently digging into a bug that popped up out of nowhere. I've had flawless syncing for 5 months, then a new user says his data is not syncing between iPad and iPhone, and now I'm experiencing the same on my devices. The debug builds worked fine, the production builds are intermittently not syncing and I have bad requests in my CloudKit log.

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Answer 2

ivan-konov OP

1w

I have had the same issue with SwiftData and CloudKit after iOS 26 release. My setup is super minimal and using the default configuration so no clue what could have gone wrong on my side.

0