Reminders cannot be marked complete since upgrade to macOS Tahoe (both 26.0 and 26.0.1)

FrankBesseling wrote:

When I mark a reminder to 'done' on my iMac I click the radio button. The button turns to filled, but the reminder doesn't dissapear. On my iPhone & iPad & MacBook (connected via iCloud) the reminder stays 'unfinished', and when I restart the reminder app on my iMac, the reminder reappears as 'unfinished' as well.

Yours is the first report I have read for this as an issue in Tahoe.

You can try launching the Reminders.app holding the Shift key down and compare your results..

For sync issue— Sign out of your Apple ID/Account /iCloud on the Mac and back in again and compare your results

Sign in to or out of your Apple Account on Mac - Apple Support

To be proactive you can file a bug report / submit your Apple Feedback here: Product Feedback - Apple

The current stable release of Tahoe including bug fixes, security updates is macOS 26.0.1

Keep your Mac up to date - Apple Support

Keep your Mac up to date - Apple Support

ALongtimeMacUser wrote:

Same issue here. I found that quitting and restarting the Reminders app is a quick fix. However the behaviour does return, unpredictably later (could be a few minutes, could be days).

The current stable release of Tahoe  including bug fixes,  security updates  is macOS 26.1

Keep your Mac up to date - Apple Support

Keep your Mac up to date - Apple Support

To be proactive you can file a bug report / submit your Apple Feedback here:  Product Feedback - Apple

Same issue here. I found that quitting and restarting the Reminders app is a quick fix. However the behaviour does return, unpredictably later (could be a few minutes, could be days).

I have the same issue. Reminders worked perfectly before Tahoe. I tried every single “fix” I could find on the web. It might work for a day, or a few hours, then return. I have switched over to Todoist, with a ton of Shortcut automations to automatically move new reminders added via Siri to my Todoist Inbox. It was so much nicer when using Reminders with Siri, though. I sure hope this long-standing issue gets fixed.

Same issue here, I select the reminder to be complete but the circle turns grey and does not mark completed; even when I option click and select Mark Completed.

It will only work from my iPhone under the same iCloud account, please fix!

Same issue as ds_studios. Please fix!