iOS/iPadOS not syncing after 16.3 update

Our scheduling app uses iCloud to sync data between the iPad and iPhone, and has worked fine for years until 16.3 was installed on our users' devices. NO syncing at all for many users. Some users regained syncing once the scheduling app was deleted and re-downloaded from the App Store. And, some users have not gotten the sync working (negatively affecting many users' businesses.

Has anyone who uses iCloud for syncing between the iPhone and the iPad?

BTW, we contacted Apple Developers support via email days ago and have yet to receive a response of any kind, even an acknowledging receiving it.

Thanks in advance for any insights as to get Apple to respond.

iOS/iPadOS not syncing after 16.3 update
 
 
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