Creating a shortcut to call an internal company extension results in an invalid contact error

I want to create a shortcut that calls a number whose last four digits I dictate. It’s for internal company calls, and the last four digits are the in-house extensions. However it ends up with a error message.

1. Step - Dictate text - 1234
2. Step - Text +420xxxxx Dictated Text
3. Step - check Show Text: +420xxxxx1234
4. Step - Get phone numbers from Text
5. Step - check Show Phone Numbers: +420 xxx xx1 234
6. Step - Get First Item from Phone Numbers
7. Step - check Show Item From List: +420 xxx xx1 234
8. Step - Call Item From List
9. Step - Error message: Invalid Contact The value provided for the Contact in Call was invalid.

Replace xxxxx with a real phone number. I sent the post earlier, but the Apple staff instead of providing a clue, stamped the post invalid because it contained personal information, which is not true, because I used dummy phone number for the post anyway.

[Re-Titled by Moderator]

Original Title: shortcut