iCloud services not syncing across devices

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Level 1

24 points

iCloud services not syncing across devices

I have an iPhone 16 Pro (running iOS, a Mac Studio (M2 running Tahoe 26.1), an Apple Watch Series 7 (running Watch 26.1), and a MacBook Pro M1 (running Tahoe 26.1). For some reason, when I mark a reminder as completed on my watch, laptop, or Mac Studio, it does not synchronize with other devices and I get additional alerts. Likewise, when I delete an e-mail message on my phone, it sometimes does not delete on my desktop or laptop and vice-versa. Photos, Drive, Passwords, Notes, Messages, Mail, Contacts, Reminders, and Calendar are all shared to iCloud. I reboot each device once a week. Any ideas what is going on and why sometimes things fail to synchronize across the iCloud world? Thanks in advance for your troubleshooting.

Posted on Dec 11, 2025 6:15 AM

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Answer 1

Top-ranking reply

azaksalmarzur28

Level 4

1,200 points

Dec 11, 2025 6:53 AM in response to grandy1214

iCloud sync issues across Reminders and Mail are usually caused by a stalled sync session, a corrupted database on one device, mismatched service settings, or low storage. Toggle sync for Reminders and Mail, ensure IMAP is used, rebuild Mail on Mac, refresh Reminders, and check all devices are on the same Apple ID. Signing out/in or resetting sync services on the Mac often resolves persistent cases.

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Answer 2

grandy1214 Author

Level 1

24 points

Dec 11, 2025 7:17 AM in response to azaksalmarzur28

Thank you! I will try this on my devices and see what happens. I appreciate your knowledge sharing.

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