Apple watch unlock not reliable if Mac on 5ghz wifi

Thank you for figuring this out! I've spent several hours troubleshooting this on my 2014 Mac mini to no avail. I'm on the latest versions of MacOS, iOS and WatchOS (same as you).

Looking in the log I've been getting:

271 sharingd: [com.apple.sharing.AutoUnlock] Client ack'd did fail with error: Error Domain=SFAutoUnlockErrorDomain Code=137 "Ranging Timeout: Results Not Returned" UserInfo={NSLocalizedDescription=Ranging Timeout: Results Not Returned}

which wasn't terribly helpful in figuring out the actual problem (I thought maybe my watch was too far away from the mini or there was interference of some kind. No amount of rebooting, signing in and out of iCloud, etc. made any difference. But then I found a link to your post and tried switching to the 2.4GHz SSID of my WiFi network-->Boom, auto-unlock worked right away. Switched back to 5GHz-->timed out. I've repeated this several times now with the same result each time.

So it's great to be able to get this working, but obviously I'd rather not have to use the slower 2.4GHz band on my Mac. What I'm wondering now is how/if this behavior differs if your 2.4/5GHz SSIDs are named the same. I have different names for mine which I had heard was best practice. But I've also seen people use the same SSID name for both networks without major problems. Have you tried that? If I get some more time this week I might give it a shot and see if it makes any difference.

Thank you again for figuring it out and posting such a detailed write-up!

Yeah that other thread is how I found this one haha.

I use PFSense running in a virtual machine as my router. APs are Netgear Prosafe WAC720's.

I'll see if I can rename my SSIDs to the same name here at some point.

Edit: I wonder if this has anything to do with the fact that the watch only has a 2.4GHz radio. From what I read, the watch will inherit the SSID your phone is on. But what if the SSID your phone is on is 5GHz only? I assume in that case the watch doesn't join any WiFi network and only relies on the bluetooth connection. Whereas if both 5GHz and 2.4GHz networks use the same SSID/password, I would guess the watch would be able to join the 2.4GHz radio while the phone stays on the 5GHz band.

No idea if that is relevant but thought I would throw it out there.

Right you are. I made sure my watch was on the 2.4GHz SSID and auto unlock still timed out. I see now you discussed that in your posts in the other thread.

You mentioned you don't have a problem at work. Do you happen to know if the access point(s)/router(s) used there are 802.11ac? I wonder if it happens with 802.11n gear (which is also capable of 5GHz and 2.4GHz).

I had similar issue with MacPro. Turned out after I read all answers below about measuring response time that 2.4GHz or 5GHz did not do much of the difference for me.

I run the command provided which is very useful, got following back :

2017-03-02 19:37:34.924096-0500 0x4228e Default 0x0 394 sharingd: [com.apple.sharing.AutoUnlock] Client ack'd did fail with error: Error Domain=SFAutoUnlockErrorDomain Code=137 "Ranging Timeout: Results Not Returned" UserInfo={NSLocalizedDescription=Ranging Timeout: Results Not Returned}

Basically, too slow to get results on time.

I tried to change AirPort Extreme to present 5GHz SID separately and connect only to 2.4GHz. Not much luck here. However what really made difference is cleanup of cables and wires (HDMI, USB, Network, Power etc) which I had between me and MacPro (it sits very close on the little table behind my desk). After all of cables were moved aside communication works pretty stable. So, in case you have MacPRO and got issue authenticating with iWatch, you might need to make sure there are not many active cables between you and your machine.

zolegus I could hug you. This solved my Auto-Unlock Issue on the Apple Watch.

So I too am on a 5 ghz network. I switched to 2.4 and was still getting the same result. One thing you said made me think ... Na it couldn't be that but what the **** I will try it.

"After all of cables were moved aside communication works pretty stable. So, in case you have MacPRO and got issue authenticating with iWatch, you might need to make sure there are not many active cables between you and your machine."

You see I have an early 2015 MBP that I use on this monitor stand - https://www.amazon.com/Allsop-Monitor-18-Inch-platform-keyboard/dp/B003M2YDE2 and I recently placed an External WD HD underneath on its side for occasional Storage. The moment I moved the External HD EVERYTHING just worked. Be aware those having auto unlock problems. Look for interference around your Mac.

I hope this helps someone else with this Auto-Unlock Issue on the Apple Watch.

Holy crap - that worked for me too! I had three WD hard drives all plugged into a hub velcroed to my laptop mount, along with three other active USB3 cables (which are known to cause interference on 2.4GHz), and once I moved them all away from the 2014 rMBP and behind my stereo, unlock with the watch works every time!

The only catch is that it doesn't work in clamshell mode, which is how I prefer to work, with my external monitor only. So now I'll just leave the MacBook open, for unlock with watch to work every time.

Note: I'm plugged into gigabit ethernet via thunderbolt (highest network priority), and also on a 5GHz WiFi connection on the rMBP, and this solution still works. I did connect to the 2.4GHz network once on my iPhone, then disabled bluetooth, and waited for the watch to learn that 2.4GHz network; however, after setting that up, I'm leaving everything else on 5GHz, and it was just the USB3 cables causing issues for me.

So glad to have figured this out!