Siri can`t call ( iPhone SE )

Hello,

A regular phonenumber I use to call ( with Siri in my car ), was changed. Now Siri can` t call that new number, she doesn't find it. When I call manually, no problem ( version 11.1.2 ).

Also, when I say " Hey Siri " she reply` s with the normal "yes? " but then I have to push the button to putt my question. ( not save driving, can't use it handsfree ). Before the update to IOS 11, there was no problem.

I did not update OTA, but with the iMac. And I restarted my phone.

What seems to be the problem?

Greetings,

Maurice