Q: Cant answer call

Hello there, frantisek88.

It seems you're unable to answer/decline an incoming phone call on your iPhone. The following Knowledge Base article, although written for troubleshooting apps installed on your device, offers some great initial steps to try:

If an app you installed unexpectedly quits, stops responding, or won’t open

Restart the app

Close the app and open it again.

Restart your device

Turn your device off and back on.

Check for iOS and app updates

Make sure that you're using latest version of iOS.

If the normal restart doesn't resolve it, you may also try to perform the Force Restart step.

Thanks for reaching out to Apple Support Communities.

Kind Regards.