apple watch won't unlock Mac

I SAY AGAIN. THE WATCH IS SIGNED INTO iCloud on the same network WITH the SAME AppleID. WiFi AND Bluetooth BOTH are active.

I've been following this glitch for YEARS through at least four MacOS, iOS, and WatchOS versions. I've not found way to replicate the spontaneous failure NOR a straight-forward, reliable means of restoration. Any attempt to turn the function back on in MacOS System Settings results in the following BOGUS message (The Mac, iPhone, AND Watch ALL are on the SAME WiFi network and signed into the SAME AppleID):

Replies that ignore the posted problem, disbelieve what the post referred to actually says, or offer irrelevant advice are not helpful.

FindMy from iCloud.com locates the Watch. Would that be possible if the watch was not active on WiFi?

The Watch app on the iPhone says the watch is signed into the same AppleID as the Mac and the iPhone.

What do you make of the MacOS System Preferences error message?

Thank you for your replies. We are all Apple users, like yourself in the community. Volunteers, doing the best we can to help. Long standing problems do sometimes get resolved, through thoroughly eliminating all the possible causes one by one. Thank you for your patience.

OK, this procedure worked ONCE. My problem has been that whatever seems to work doesn't work consistently. So, I'll let you know if it works over and over again.

This is a four year old (at least) issue that Apple has been ignoring over successive major updates of MacOS, iOS, and WatchOS. The setting turns itself from on to off spontaneously without apparent cause. Attempting to turn it back on produces this obsolete, and therefore totally useless diagnostic--

That message only confuses the issue. A setting that had been working stops, BUT the Mac, iPhone, and Watch all remain signed into a common iCloud and Apple-ID, using the same WiFi Network, and all are linked together through Bluetooth (turning Bluetooth off and back on has no effect BTW), according to Apple's support pages it *should* be possible to turn Use Apple Watch to unlock your Mac back on. However, attempting to do so fails and produces the above nonsense diagnostic.

There are numerous long strings on this topic in the support communities that searching for a topic often overlooks. It's way past time for Apple to fix this bug.

This is at least a 4 year old bug. You'll find LOTS of comments. Many of them misguided. The December 27, 2023 comment by Inaworldofhurt is the best one I've read so far. Maybe it will work for you, if you can get the really awful early 1990's search function that communities uses to find it.

That bogus message does say that. Let us know when you find a way to use the Watch app to sign into iCloud--a screen shot would be nice. The Watch app should confirm that the Watch is signed into an AppleID.

IF the Watch had been unlocking the Mac and suddenly stopped doing so; you are likely to find: 1) the Watch is still signed into the same AppleID as the Mac and the phone, 2) all three are active on the same WiFi network, 3) Bluetooth is on for all 3 devices AND the Bluetooth setting on the iPhone indicates that it is paired with the Watch.

In short, ALL of the requirements for the Watch unlocking the Mac are met, yet it doesn't. Now what?

Thank you kindly, CMatheso, for sharing your solution here, where it may help others who are looking for answers! Good to know you no longer have that issue. Cheers!

That does seem to work if you really are willing to go to that much hassle. This solution won't last long enough for it to be useful as a regular fix.