Tahoe 26.5.2 Apple Watch sign on fails
2021 MacBook Pro M1-Max CPU, 32 GB RAM. It SAYS signing on with Apple Watch. It spins a little and then simply stops. That is, it recognizes the iWatch 10. The sign no with Apple Watch setting is active. It seems to try, but it doesn't succeed. It worked fine with earlier versions of Tahoe. Some glitch introduced by 26.5.2. Restart doesn't help.
MacBook Pro 14″, macOS 26.5
The behavior you describe suggests that the Mac is detecting the Apple Watch correctly, but the final authentication step is failing.
Since the Mac displays “Signing in with Apple Watch” and begins the process before stopping, the connection between the two devices appears to be working, but the authorization is not completing.
Because the feature worked before the macOS Tahoe 26.5.2 update, it is possible that the update introduced a compatibility issue or a software bug.
Before assuming that, it is worth resetting the Apple Watch sign-in feature.
Open System Settings on the Mac, go to the Touch ID and Password section, and turn off the option to use Apple Watch to unlock the Mac.
Wait briefly, then enable the option again and enter the Mac password if requested.
Confirm that Bluetooth and Wi-Fi are enabled on both devices, that both devices are signed in to the same Apple Account, that two-factor authentication is enabled, and that the Apple Watch is unlocked and being worn.
Restart both the Mac and the Apple Watch. For the Apple Watch, perform a full power off and restart rather than only restarting the Mac.
It is also important to confirm that the Apple Watch is running the latest compatible version of watchOS 26.5
Some macOS updates can affect Continuity features and require matching updates on connected devices.
If the problem continues after resetting the feature, and the issue began immediately after installing macOS Tahoe 26.5.2, it may be a software regression in that release.
Though my iWatch series 11 works just fine with a M4 Desktop with macOS 26.5.2
The behavior you describe suggests that the Mac is detecting the Apple Watch correctly, but the final authentication step is failing.
Since the Mac displays “Signing in with Apple Watch” and begins the process before stopping, the connection between the two devices appears to be working, but the authorization is not completing.
Because the feature worked before the macOS Tahoe 26.5.2 update, it is possible that the update introduced a compatibility issue or a software bug.
Before assuming that, it is worth resetting the Apple Watch sign-in feature.
Open System Settings on the Mac, go to the Touch ID and Password section, and turn off the option to use Apple Watch to unlock the Mac.
Wait briefly, then enable the option again and enter the Mac password if requested.
Confirm that Bluetooth and Wi-Fi are enabled on both devices, that both devices are signed in to the same Apple Account, that two-factor authentication is enabled, and that the Apple Watch is unlocked and being worn.
Restart both the Mac and the Apple Watch. For the Apple Watch, perform a full power off and restart rather than only restarting the Mac.
It is also important to confirm that the Apple Watch is running the latest compatible version of watchOS 26.5
Some macOS updates can affect Continuity features and require matching updates on connected devices.
If the problem continues after resetting the feature, and the issue began immediately after installing macOS Tahoe 26.5.2, it may be a software regression in that release.
Though my iWatch series 11 works just fine with a M4 Desktop with macOS 26.5.2
A very similar problem with my Apple Watch not unlocking my Mac was solved when I toggled the "Log out automatically after inactivity" off. The update must have toggled it on. I noticed after my watch no longer unlocked my Mac, that open applications were no longer open when I unlocked my Mac using password. Toggling this feature off solved (found at bottom of Privacy and Security under advanced) the issue and my watch now unlocks my Mac. Hope this helps.
It seems that glitch reappears with nearly every macOS update.
I advise doing nothing for a day or two, because that has always worked for me. Same exact symptoms. I did exactly nothing and a couple days later it simply started behaving again.
If it still doesn't work, or if you grow impatient, or just morbidly curious:
Done.
For reference: Unlock your Mac with your Apple Watch - Apple Support
👍
It might have. I'll make note of it.
Way at the bottom of Unlock your Mac with your Apple Watch - Apple Support, under "If you're having difficulty getting Auto Unlock to work," it states:
The "restart your Mac" part is easily overlooked. Having said that, it is one of the steps I tried in the past to no avail. The eight step procedure I described above covers that as well as other possible factors.
It has been an ongoing problem for years now, across many different Mac models.
Happily, that worked; Thanks. I didn't try just turning off "unlock with Apple Watch" and turning it back on again. That would have been simpler. Maybe that alone would have worked; maybe not.
Apple Watch sign-on fails on Mac after Tahoe 26.5.2 update
