Location extension, specially the phone number is importing incomplete as the phone number is missing a "0" at beginning of the number.
For DE Market it´s standard to show the phone number beginning with a "0".
The UCM above confirms that is not possible at the moment for Advertising as per design.
In Google Adwords there are no restrictions so the location extension gets imported incomplete when clients are importing from Google to Advertising.
Please update the UI as phone numbers beginning with "0" is a german standard.