[donawalt]

I have never seen this before, but several times now I have tried 'forgetting' my home WiFi network on my iPhone, so I could do temporarily something on the cell signal, and I find that the WiFi network has been forgotten on my MacBook Pro too! When I join the network on my phone I also have to go and join the network on my MacBook.

I am pretty sure this is new behavior in iOS 11. Has anyone seen this or have an explanation?

Thanks!

[Tartarus]

I have never seen this before, but several times now I have tried 'forgetting' my home WiFi network on my iPhone, so I could do temporarily something on the cell signal, and I find that the WiFi network has been forgotten on my MacBook Pro too! When I join the network on my phone I also have to go and join the network on my MacBook.

I am pretty sure this is new behavior in iOS 11. Has anyone seen this or have an explanation?

Thanks!

Wifi passwords are saved on iCloud Keychain. Forgetting it removes that password from all devices using the same iCloud account.

Instead of forgetting, it would be easier for you to disable wifi.

[donawalt]

Ah that makes perfect sense Tartarus! Thank you. I knew there had to be a logical explanation.

Now I noticed my iPad did not disconnect. Is the password saved differently there?

[Tartarus]

I’m not sure. It could be that the WiFi chip on the MacBook is inherently different from the iPad one and therefore can handle the instantaneous disconnecting much better.

But I’m just guessing here.
Hopefully someone else with more knowledge can shed some light on this.

[doogald]

Now I noticed my iPad did not disconnect. Is the password saved differently there?

Check to see (in iCloud settings) if you have iCloud Keychain sync turned on in the settings on the iPad. If it's not, perhaps that explains it? It could also be that iOS devices behave differently from MacOS - when you forget the network, it's only affected the next time that you try to connect.

You could test this with the Mac and iPhone by forgetting the passcode on the Mac and see what happens on the iPhone, which you know already are keychain synced.

[donawalt]

A good guess, I thought you might have nailed it - but alas keychain is selected in iCloud for all 3 (iPad, iPhone, Mac).