Cannot connect iPhone to MacBook


Since a couple of days I cannot connect my iPhone 13 Pro Max (iOS 16.1.2) to my MacBook Pro (macOS Monterey 12.6.1) via USB cable. The iPhone shows up in the Finder window on the left side, but does not connect. (Also iMazing does not connect.)

Here is what I did, alas to no avail:
– restart both the iPhone and the MacBook (also in Safe Boot)
– use another cable.
– use another MacBook (same result)
– resetting Trust (Settings > General > Transfer or Reset [Device] > Reset > Reset Location & Privacy)
– checking AirPort (doesn’t work)
– switching off/on Bluetooth

Strangely, I could copy a photo from my iPhone to my MacBook.

Since my wife’s iPhone connects correctly to my MacBook it seems to indicate that the problem is with my iPhone.

Today I spent more than half an hour at Apple’s Genius Desk where we more or less repeated what I had tried before.

The guy at the Genius Desk, too, came to the conclusion that the problem is with my iPhone. He suggested resetting the Network Settings. I would rather not do this since I will be losing the – to me mostly unknown – passwords of the many WiFi’s I used in the last year.

He also suggested that in the end I would have to reset the iPhone completely which seems to be a bad idea since I have no easy access to a backup to restore from. (The iPhone backups are stored locally on my MacBook and because of the connection problem they are not easily accessible.) I would not want to backup to iCloud.

Any ideas how to solve my problem?

Thanks for your attention.

If you share your Keychain using iCloud, then it will get saved. This means that resetting the Network settings on the phone won’t remove all your wifi passwords.

Assuming you use the same AppleID on your desktop machine, you can confirm that the wifi connections are being saved/shared correctly by looking at the Network settings on the desktop Mac. Choose the Wi-Fi connection and then look at the list of Preferred Networks. If all the ones only ever used on your phone are listed, you should be good to go.

Unless something has changed with iOS 16, this has not been my experience with Reset Network Settings. It has always been that I’ve needed to reestablish and enter the passphrase when I am connecting to known networks for the first time. (Again, my experience has been with iOS 15 and older, so this may be new with iOS 16.)

Indeed. The passwords perhaps get saved and synced through iCloud, but you still lose iPhone settings such as which networks to join automatically, which are known, etc.

Nuking network settings when you have a lot of stored information there should thus IMHO only be done when there is a clear expected benefit. If OTOH you’re just doing it to tick off boxes or because some low-level supporter is out of ideas (like rebooting or “repair permissions” back in the old days), chances are you won’t gain anything, but you’ll lose a bunch of stuff that will be a pain to set up again from scratch.

Dan, Doug, Simon: Many thanks for your comments to my problem.

Today, I switched all network settings on and off individually – avoiding the general Reset Network Settings – and finally, by luck, I found the culprit.

It is ProtonVPN. Once it is activated, my iPhone can no longer connect to my MacBook. Once it is deactivated, there is no connection problem.

This is very strange since I have been using ProtonVPN for quite some time without any problem. Perhaps it it the latest update that causes the connection problem.

I just sent an error report to Proton.

This is a common feature of VPN software (especially VPNs used to grant access to corporate networks). They redirect all traffic into the VPN, making your local LAN and anything on it inaccessible.

When I use my employer’s VPN to access their servers, I can’t access anything on my LAN (file server, web server, printer, etc.) until I disconnect the VPN.

If your VPN just started doing this, check its configuration. Look for something like “split tunneling” and enable the feature if it is off. This buzzword refers to the ability to connect to the VPN while retaining other network access. It’s less secure (because your computer could end up forwarding malicious data between your LAN and the VPN), but it’s something you probably want to have on when you’re connected to your home network (where you can, hopefully, trust what’s connected).

1 Like

Getting response from Proton, I realised that I had enabled the Kill Switch of ProtonVPN on my iPhone which prevents the iPhone from accessing devices on my local LAN.

Once I disabled the Kill Switch, the connection problem disappeared.

Thus in the end, I was the culprit.

1 Like