After updating to 17.0.2, when I try to make a call my iPhone says connection failure

Hello Olja-,

Welcome to Apple Support Communities. We understand that you’re unable to make calls. We are happy to help.

Please try the steps here: If you can't make or receive calls on your iPhone - Apple Support

"Contact your carrier

When you contact your carrier, make sure that:

• Your account is set up to use your iPhone.
• There aren't any localized service outages.
• Your account doesn't have a billing-related block.
• Your calls don't have errors on the carrier system.

Update your software

1. Check for a carrier settings update.
2. Check for an iOS software update. Some updates might require a Wi-Fi connection.

Check your settings

If you can't make or receive calls on your iPhone, follow these steps, testing after each step.

Check your network settings

1. Reset your network settings. Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This will erase all current saved settings, including Wi-Fi passwords, preferred networks, and VPN settings.
2. Try to make or receive calls in another location.
3. 
   

Check your iPhone settings

1. Turn Airplane Mode on and off. Go to Settings and turn on Airplane Mode, wait five seconds, then turn it off.
2. Check Do Not Disturb. Go to Settings > Focus > Do Not Disturb and make sure it's off. Learn how to use Focus on your iPhone or iPad.
3. Check for any blocked phone numbers. Go to Settings > Phone > Blocked Contacts.
4. Check Call Forwarding. Go to Settings > Phone > Call Forwarding and make sure it's off.
5. Check Silence Unknown Callers. Go to Settings > Phone > Silence Unknown Callers. If the setting is on, a caller must be listed in your Contacts or Recents. Or they must have shared their number in Mail or sent you a message using that number in order for their call to go through. Add their number to Contacts to ensure the phone rings. Calls from some third-party apps might not go through.

To avoid missing calls from a contact, add their number to Contacts to ensure that your phone rings.

Learn more

• Find out what to do if "No Service" or "Searching" appears in the status bar.
• If you still can't make or receive calls, contact Apple Support, then follow the steps to complete your request."

If your phone is showing no service, please try the steps here: If you see No Service, Searching, or SOS on your iPhone or iPad - Apple Support

"Check your coverage area

• Make sure that you're in an area with cellular network coverage.
• Turn cellular data off and then back on again. Go to Settings, then tap Cellular or Mobile Data. If you're using an iPad, you might see Settings > Cellular Data.
• If you're traveling internationally, make sure that your device is set up for data roaming. Go to Settings > Cellular > Cellular Data Options > Data Roaming.

If you see SOS or SOS only

If you see SOS or "SOS only" in the status bar, your device isn't connected to a network, but you can still make emergency calls. This feature is available in Australia, Canada, and the United States.

Restart your iPhone or iPad

Restart your device. If you're not sure how to do this, follow these steps to restart your iPhone or restart your iPad.

Check for a Carrier Settings update

To manually check for and install a carrier settings update:

1. Make sure that your device is connected to a Wi-Fi or cellular network.
2. Tap Settings > General > About. If an update is available, you'll see an option to update your carrier settings.
3. To see the version of carrier settings on your device, tap Settings > General > About and look next to Carrier.

If you insert a new SIM card into your iPhone or iPad, you need to download the carrier settings for your new carrier.

Turn your cellular line off and back on

Go to Settings > Cellular and check to see if your cellular line is turned on. If your cellular line is off, turn it back on. Then check to see if you have service.

If you don't see your cellular line in Settings > Cellular, you should set up an eSIM or insert a physical SIM card. 

If you're using a physical SIM card, remove the SIM card and put it back in.

If your SIM card is damaged, doesn't fit in the SIM tray, or you transferred your physical SIM card from another device, ask your carrier for a new SIM card. 

Learn more about removing your iPhone SIM card or iPad SIM card.

Reset your Network Settings

Go to Settings > General > Transfer or Reset [Device] > Reset > Reset Network Settings. This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before.

Update your iPhone or iPad

Update your iPhone or iPad to the latest version of iOS or iPadOS.

Contact your carrier 

Issues with your carrier or account might affect your service. Contact your carrier to:

• Verify that your account is active and in good standing.
• Make sure that there are no outages in your area.
• Check that your device isn't blocked from receiving cellular services and is set up with the right data plan.

Only your wireless carrier can access and manage details about your account:

• iPhone wireless carriers
• iPad wireless carriers

Get more help

If your carrier confirms that there's no issue with your account or network, but you still can't connect to a cellular network, contact Apple Support.

If you see an alert next to No Service, learn what you can do."

These steps may help. Please let us know if you have further questions.

Take care.

I can’t get my emergency bypass numbers to ring. I need it